Chemistry HP Unit 2 â The Atom Learning Targets (Your exam at the ...
Chemistry HP Unit 2 – The Atom Learning Targets (Your exam at the end of Unit 2 will assess the following:) 2. Atomic Structure and Electron Configuration 2-1. Give the one main contribution to the development of the atomic model from each of the following scientists: Dalton, Thomson, Rutherford, Chadwick, and Bohr. 2-2. Identify elements by both name and chemical symbol using a periodic table. 2-3. Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom. 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element. 2-5. Define isotope and state how the atomic structure for isotopes of the same element are similar and different. 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope. 2-7. Define valence electrons and determine the number of valence electrons for an atom. 2-8. Locate rows/periods and groups/families on the periodic table. 2-9. Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. 2-10. Define ion and determine the charge for the ion of an element from the periodic table. Determine the number of electrons for an ion. Give the symbol for the ion. 2-11. Define cation and anion. 2-12. Define and give examples of electromagnetic radiation. 2-13. Define wavelength and frequency and state the units used to measure each quantity. 2-14. Perform calculations involving wavelength, frequency, and energy, giving answers with the appropriate units and significant figures. 2-15. Describe the experiment used to show the photoelectric effect and the significance of the findings by defining a photon 2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. 2-17. List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold. 2-18. Give orbital notation for a given atom/ion by applying the Aufbau Principle, Hund’s Rule, and the Pauli Exclusion Principle. 2-19. Write electronic configuration for a given atom/ion. 2-20. Write noble gas configuration for a given atom/ion. 2-21. Recognize an excited state for a given element. 2-22. Give two elements that are exceptions to the regular electron configuration rules and write the actual configuration for these elements.
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2-1. Give the one main contribution to the development of the atomic model from each of the following scientists: Dalton, Thomson, Rutherford, Chadwick, and Bohr. Scientist
Experiment
Findings
Dalton
Thomson
Rutherford
Chadwick
Bohr
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2-2. Identify elements by both name and chemical symbol using a periodic table. 2-3. Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom. 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element. Subatomic Particles Name
Symbol
Symbol
Name
24 11
𝑁𝑎
80 35
𝐵𝑟
40 20
𝐶𝑎
197 79
𝐴𝑢
16 8
𝑂2−
39 19
𝐾+
Charge
Relative Mass
Atomic Number
Mass Number
34
78
22
47
91
231
Number of Protons
Actual Mass (g)
Number of Neutrons
Location
Number of Electrons
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WS #1 (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.
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WS #1 (con’t) (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.
(11) Complete the following table for neutral atoms and/or ions. Substance
symbol
Magnesium
atomic number
mass number
12
24
Iron
S
Beryllium
16
Pt+3
Atom or ion?
atom 13
16
9
atom 24
194
U+2 Oxygen
number of electrons
24
13
24 Platinum
number of neutrons
12 26
26 Sulfur
number of protons
24 75
92
O2-
143 8
Gold 45
18
18
118
78
24 74
-1 ion
22 70
+2 ion
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Substance
symbol
atomic number
mass number
number of protons
number of neutrons
number of electrons
Atom or ion?
Magnesium
Mg
12
24
12
12
12
atom
Iron
Fe
26
50
26
24
26
atom
Aluminum
Al
13
26
13
13
13
atom
Sulfur
S
16
32
16
16
16
Atom
Beryllium
Be
4
9
4
5
4
Atom
Chromium
Cr
24
48
24
24
24
Atom
Platinum
Pt+3
78
194
78
116
75
+3 ion
Uranium
U+2
92
235
92
143
90
+2 ion
Oxygen
O2-
8
16
8
8
10
-2 ion
Chlorine
Cl-
17
35
17
18
18
-1 ion
Gold
Au+
79
197
79
118
78
+1 ion
Chromium
Cr+2
24
45
24
21
22
+2 ion
Tungsten
W+2
74
144
74
70
72
+2 ion
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2-5. Define isotope and state how the atomic structure for isotopes of the same element are similar and different. 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope. Isotopes are atoms of the _____________ _________________ that have _______________ numbers of ______________. Isotope
Carbon-12
Carbon-13
Carbon-14
Atomic Number
Mass Number
Number of Protons
Number of Neutrons
Mass Number is the number of ________________ and _________________ in an atom. Atomic Mass is the ______________________ _______________________ ___________________ of all the different isotopes of an element ____________________ by the abundance of each isotope in nature. Atomic mass is measured in Atomic Mass Units (_______) (1 amu = 1/12 the mass of a carbon-12 atom)
Example: Silver (atomic number 47) has two naturally occurring isotopes, Ag-107 and Ag-109. Given their atomic masses and percent abundances below, what is silver’s average atomic mass? Isotope
Mass (amu)
Abundance (%)
Ag-107
106.90509
51.84
Ag-109
108.90476
48.16
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Example: Silicon (atomic number 14) has three naturally occurring isotopes, Si-28, Si-29 and Si-30. Given their atomic masses and percent abundances below, what is silicon’s average atomic mass? Isotope
Mass (amu)
Abundance (%)
Si-28
27.976927
92.23
Si-29
28.976495
4.67
Si-30
29.973770
3.10
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WS #2 (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)
(1) Isotopes are different “versions” of the same atom that have the same number of _____________ but different numbers of _____________ and therefore different _____________ _____________. (2) How many neutrons does each isotope have? (a) Carbon-13
(b) Oxygen-18
(c) Potassium-40
(d) Scandium-45
(e) Manganese-55
(f) Tungsten-186
(3) There are two isotopes of copper: Copper-63 (69.17%) and Copper-65 (30.83%). (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of copper (round your answer to one decimal place).
(4) There are two isotopes of silver: Silver-107 (51.84%) and Silver-109 (48.16%). (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of silver (round your answer to one decimal place).
(5) There are three isotopes of magnesium: Magnesium-24 (78.7%), Magnesium-25 (10.1%), and Magnesium-26 (11.2%) (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of magnesium (round your answer to one decimal place).
(6) There are four isotopes of iron: Iron-54 (5.85%), Iron-56 (91.75%), Iron-57 (2.12%), and Iron-58 (0.28%) (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of iron (round your answer to one decimal place).
(7) There are two isotopes of gallium: Gallium-69 and Gallium-71. (a) Determine the number of neutrons in each of the isotopes. (b) Gallium-69 has an abundance of 60.11%, what is the abundance of Gallium-71? (c) Calculate the average atomic mass of gallium (round your answer to one decimal place).
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WS #2 (con’t) (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)
(8) There are two isotopes of bromine: Bromine-79 and Bromine-81. (a) Determine the number of neutrons in each of the isotopes. (b) Bromine-79 has an abundance of 50.69%, what is the abundance of Bromine-81? (c) Calculate the average atomic mass of bromine (round your answer to one decimal place).
(9) There are five isotopes of germanium: Germanium-70, Germanium-72, Germanium-73, Germanium-74, and Germanium-76 (a) Determine the number of neutrons in each of the isotopes. (b) Germanium-70 has an abundance of 21.23%, Germanium-72 has an abundance of 27.66%, Germanium-73 has an abundance of 7.73%, and Germanium-74 has an abundance of 35.94%. What is the abundance of Germanium-76? (c) Calculate the average atomic mass of germanium (round your answer to one decimal place).
(10) There are four isotopes of strontium: Strontium-84, Stronium-86, Strontium-87, and Strontium-88. (a) Determine the number of neutrons in each of the isotopes. (b) Strontium-84 has an abundance of 0.56%, Strontium-86 has an abundance of 9.86%, and Strontium-87 has an abundance of 7.00%. What is the abundance of Strontium-88? (c) Calculate the average atomic mass of strontium (round your answer to one decimal place).
Answers: Isotopes (1) Isotopes are different “versions” of the same atom that have the same number of protons but different numbers of neutrons and therefore different atomic masses (2) (a) 7 (b) 10 (c) 21 (d) 24 (e) 30 (f) 112 . (3) (a) 34, 36 (b) 63.6 amu (4) (a) 60, 62 (b) 108.0 amu (5) (a) 12, 13, 14 (b) 24.3 amu (6) (a) 28, 30, 31, 32 (b) 55.9 amu (7) (a) 38, 40 (b) 39.89% (c) 69.8 amu (8) (a) 44, 46 (b) 49.31% (c) 80.0 amu (9) (a) 38, 40, 41, 42, 44 (b) 7.44% (c) 72.67 amu (10) (a) 46, 48, 49, 50 (b) 82.58% (c) 87.7 amu 10
2-7. Define valence electrons and determine the number of valence electrons for an atom. 2-8. Locate rows/periods and groups/families on the periodic table. 2-9. Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion.
Periods on the periodic table go ______________ and __________________. Groups on the periodic table go ______________ and __________________. Valence Electrons =
How to determine the number of valence electrons an atom has:
Sample Problem. How many valence electrons? Carbon Magnesium Chlorine Helium
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WS #3 (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
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WS #4 (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
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WS #4 (con’t) (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
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2-12. Define and give examples of electromagnetic radiation. 2-13. Define wavelength and frequency and state the units used to measure each quantity. 2-14. Perform calculations involving wavelength, frequency, and energy, giving answers with the appropriate units and significant figures.
All waves of the _____________________ _________________________ travel at the ________________ _____ ________________, approximately c = 3.00 x 108 m/s The relationship between wave speed, wavelength and frequency is given by the equation:
𝑐 = 𝜈𝜆 c = speed of light 3.00 x 108 m/s 𝜈 = frequency (in s-1 or Hz) 𝜆 = wavelength (m)
The greater the frequency, the _______________ the wavelength. The lower the frequency, the ________________ the wavelength. Wavelength and frequency are __________________ proportional.
Sample Problem. A certain photon of light has a wavelength of 422 nm. What is the frequency of the light?
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Sample Problem. What is the wavelength of a photon of light whose frequency is 5.0 x 1015 Hz ?
Energy and Frequency
𝐸 = ℎ𝜈 E = Energy (J) h = Planck’s constant, 6.626 x 10-34 Js 𝜈 = Frequency
Sample Problem. A certain green light has a frequency of 6.26 x 1014 Hz. What is the energy of one photon of this light?
Sample Problem. A certain source emits radiation of wavelength 500.0 nm. What is the energy, in J, of one of its photons?
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WS #5 (Learning Targets 2.12. Define and give examples of electromagnetic radiation. 2.13. Define wavelength and frequency and state the units used to measure each quantity. 2.14. Perform calculations involving wavelength, frequency, and energy, giving answers with the appropriate units and significant figures. )
Answer the following questions in the space provided. For any calculation, give the equation used to solve the problem and answer with appropriate units and significant figures.
(1) Wavelength is written using the variable ______ which has a symbol of ____ and units of _________ which are given the symbol ____. (2) Frequency is written using the variable ______ which has a symbol of ____ and units of _________ which are given the symbol ____. (3) The speed is light is written using the variable ______ and is equal to __________________. (4) The higher the frequency, the _______________ the wavelength. The lower the frequency, the _______________the wavelength. (5) Which has a longer wavelength˗ gamma rays or microwaves? (6) Which has a higher frequency˗ ultraviolet or infrared radiation? (7) A microwave has a frequency of 4.0x1010 Hz. Determine the wavelength.
λ = ____________________
(8) A gamma ray has a wavelength of 2.40x10˗12 m. Determine the frequency.
ν = ____________________
(9) Infrared radiation has a frequency of 8.40x1013 Hz. Determine the wavelength.
λ = ____________________
(10) A radiowave has a wavelength of 20.5 m. Determine the frequency.
ν = ____________________
(11) A radio wave has a frequency of 91.5 MHz. Determine the wavelength.
λ = ____________________
(12) The color violet can have a wavelength of 390 nm. Determine the frequency.
ν = ____________________
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WS #5 (Con’t) (13) Albert Einstein proposed that light is a stream of particles called _______________. _______________ have a specific energy depending on their wavelength/frequency and can be thought of as massless “packets of _______________”. Einstein proposed this idea to explain the results of the __________________ effect experiment. In this experiment, light of a specific wavelength/frequency is shined on the surface of a _______________. If the light has enough energy the _______________ will “knock” _______________ off the surface of the _______________. If the light does not have a _______________ enough energy, even if it is shined on a metal for an extended period of time, no _______________ will be emitted. Each metal has a specific amount of energy required to emit electrons. (14) Energy has units of __________ which are given the symbol ______. (15) Electromagnetic radiation with a high energy has a __________ wavelength and a __________ frequency. Electromagnetic radiation with a low energy has a __________ wavelength and a __________ frequency. (16) Which is higher in energy˗ radio waves or visible light? (17) Which is lower in energy˗ X˗rays or radiowaves? (18) Calculate the energy of light with a frequency of 8.4x1020 Hz.
E = ____________________
(19) Calculate the energy of light with a wavelength of 2.50x10˗7 m.
E = ____________________
(20) The laser in a CD player uses light with a frequency of 3.85x1014 Hz. Determine the wavelength of the light from the laser. Calculate the energy of a photon with this frequency. λ = ____________________ E = ____________________ (21) Excessive exposure to ultraviolet light can cause skin cancer and retinal damage. Damaging ultraviolet light has a wavelength of 1.5x10˗9 m. Determine the frequency of UV light. Calculate the energy of a photon with this wavelength. ν = ____________________ E = ____________________ (22) It takes 7.21 x 10–19 J of energy to remove an electron from an iron atom. Determine the frequency and wavelength of a photon of light that could accomplish this. ν = ____________________ λ = ____________________
Answers: (1) Wavelength is written using the variable lambda which has a symbol of λ and units of meters which are given the symbol m. (2) Frequency is written using the variable nu which has a symbol of ν and units of Hertz which are given the symbol Hz. (3) The speed is light is written using the variable c and is equal to 3.00x108 m/s. (4) The higher the frequency, the lower the wavelength. The lower the frequency, the higher the wavelength. (5) microwaves (6) ultraviolet (7) 7.5x10˗3 m (8) 1.25x1020 Hz (9) 3.57x10˗6 m (10) 1.46x107 Hz (11) 3.28 m (12) 7.69x1014 Hz (13) Albert Einstein proposed that light is a stream of particles called photons. Photons have a specific energy depending on their wavelength/frequency and can be thought of as massless “packets of energy”. Einstein proposed this idea to explain the results of the photoelectric effect experiment. In this experiment, light of a specific wavelength/frequency is shined on the surface of a metal. If the light has enough energy the photons will “knock” electrons off the surface of the metal. If the light does not have a high enough energy, even if it is shined on a metal for an extended period of time, no electrons will be emitted. Each metal has a specific amount of energy required to emit electrons. (14) Energy is has units of Joules which are given the symbol J. (15) Electromagnetic radiation with a high energy has a low wavelength and a high frequency. Electromagnetic radiation with a low energy has a high wavelength and a low frequency. (16) visible light (17) radio waves (18) 5.6x10˗13 J (19) 7.95x10˗19 J (20) 7.79x10˗7 m, 2.55x10˗19 J (2) 2.0x1017 Hz, 1.3x10˗16 J (22) 1.09x1015 Hz, 2.76x10˗7 m 19
2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. Two problems with Bohr’s Orbital Model of the atom are: 1.
2. The photoelectric effect showed that light behaves like particles, because only light with a certain _______________ _________________ can eject electrons from a metal’s surface. That light is only given off in discrete packets of energy gives it characteristics of a ____________________. This particle is called a ___________________. A photon is a discrete bundle (or __________________) of electromagnetic (light) energy that travels at the speed of light. Therefore, whereas light is a wave of electromagnetic energy, it also behaves as a particle, a photon. Physicists, in attempting to apply Bohr’s orbital model to more complex atoms, deduced that particles as small as atoms and electrons could not be explained by the classical mechanics of Newton. They began to see a ________________ _________________ to electrons, as well as light – sometimes electrons behaved as __________________; sometimes as ____________________. The _____________________ _____________________ _____________________ shows that, when electrons are shot through two slits, they make an interference pattern like a ____________________, not a _______________________. Standing waves form when two traveling waves traveling in opposite directions at the same speed combine or run into each other. Since only certain standing waves will fit perfectly inside an atom, electrons trapped in that atom can only have certain electron ____________________ _____________________ with certain electron _________________________. This explains the quantization of energy. Schrodinger was the first person to write down a wave equation to describe the ________________ ______________________ of _____________________. It describes the __________________ of finding an electron at any point in time. Heisenberg Uncertainty Principle – it is impossible to know both the exact __________________ and _______________________ of a particle at the same time. Significance: We _________________ ___________________ ______________________ where to find an electron in an atom. Rather, we talk about _________________________ of finding an electron. Schrodinger’s equation, then, was used to find the ____________________ ____________________ __________________ of electrons and its associated _______________________ gives the _________________________ of finding the electron at a certain position. _____________________ _______________________ are the specific solutions to Schrodinger’s Equation…
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WS #6 (Learning Target 2:16: Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. ) 1.
Light acts as both a ___________________ and a ______________________.
2.
Light is absorbed and emitted in discrete packets of _____________________ known as ____________________ which describes the emission spectrum of atoms.
3.
Electrons ALSO act as both ___________________ and a ______________________.
4.
Evidence for this is the ____________________ _______________________ experiment.
5.
In the ____________________ _______________________ experiment, electrons are shot at two slits, and form ___________________________ patterns like waves.
6.
Electrons act as _______________________ waves around the nucleus.
7.
___________________ __________________ ___________________ says that you cannot know the __________________ and _______________________ of an electron at the same time.
8.
Therefore, we talk about the _____________________ of finding an electron.
9.
_______________________ developed a _________________ equation to describe the wave nature of electrons.
10. It also describes the _______________________ of finding an electron at any point in time.
Answers: (1) wave, particle (any order) (2) energy, photons (3) particles, waves (any order) (4) double slit (5) double slit, interference (6) standing (7) Heisenberg’s Uncertainty Principle, position, momentum (8) probability (9) Schrodinger, wave (1) probability
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2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. Three Important Rules: Pauli Exclusion Principle: No two electrons in an atom can have the same ____________ _____________________ __________________. Aufbau Principle: Fill from the ______________ energy level _______________. Hund's Rule: If multiple orbitals have the same energy, electrons _________________ _____________ before _________________ _________. Define the following. Type Principle Quantum Number
Symbol n
Angular Momentum Quantum Number
l
Magnetic Quantum Number
ml
Spin Quantum Number
ms
Definition
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Principle Quantum Number (n) Possible Values
Angular Momentum Quantum Number (l)
Magnetic Quantum Number (ml)
Magnetic Spin Quantum Number (ms)
Electron Configuration
Max # Electrons
Orbital Name and Shape
1
2
3
4
5
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2-14. List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold. Angular Momentum Quantum Number (l)
Orbital Letter
Orbital Shape
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WS #7 (Learning Targets 2.14: List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold and 2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define.)
1. Fill in the blanks. (a) The principle quantum number describes the _____________ level of an orbital and is given the letter designation n. The higher the principle quantum number, the _______________ the energy level of the orbital and the ____________ the size of the orbital. (b) The angular momentum number describes the ______________ of an orbital. Each shape is given a letter designation. There are four letter designations for orbitals: ____, _____, ______ and _____. (c) The magnetic quantum number gives the ________________ of the orbital. For “s” orbitals there is ________ orientation, for “p” orbitals there are ______________ orientations, for “d” orbitals there are _____________ orientations, and for “f” orbitals there are ______________ orientations. (d) The spin quantum number gives the spin of an ________________. There are two different values for the spin quantum number: ____________ or __________. A positive spin quantum number is represented as an arrow pointing ___________ and a negative spin quantum number is represented as an arrow pointing __________. Each subshell of an orbital can hold two electrons of opposite spin. 2. State the number of possible electrons described by the following quantum numbers a. n = 3, l = 0 b. n = 3, l = 1 c. n = 3, l = 2, ml = -1 d. n = 5, l = 0, ml -2, ms -1/2 3. Give the n and l values for the following orbitals a. 1s b. 3s c. 2p d. 4d e. 5f 4. What is the ml values for the following types of orbitals? a. s b. p c. d d. f 5. Write the complete set of quantum numbers that represent a valence electron for the following elements: a. He b. Ca c. At
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6. How many electrons can inhabit all of the n=4 orbitals? 7. Fill in the blanks with the correct response: a. b. c. d. e. f. g. h. i. j. k. 8.
The number of orbitals with the quantum numbers n=3, l=2 and ml = 0 is _________. The subshell with the quantum numbers n=4, l=2 is _________. The ml values for a d orbital are ________________________. The allowed values of l for the shell with n=2 are _________. The allowed values of l for the shell with n=4 are _________. The number of orbitals in a shell with n=3 is _________. The number of orbitals with n=3 and l=1 is _________. The maximum number of electrons with quantum numbers with n=3 and l=2 is _________. The number of electrons with n=4, l=1 is _________. The subshell with n=3 and l=1 is designated as the __________ subshell. The lowest value of n for which a d subshell can occur is n=_________. a. What is the value of l for a 4 f electron? b. What are the possible values of ml for a 5d electron? c. What is the maximum number of electrons in the 3rd energy level? d. How many electrons have the following quantum numbers: n =4, l = 2, ml = -2?
Answers. (1) (a) The principle quantum number describes the energy level of an orbital and is given the letter designation n. The higher the principle quantum number, the higher the energy level of the orbital and the larger the size of the orbital. (b) The angular momentum number describes the shape of an orbital. Each shape is given a letter designation. There are four letter designations for orbitals: s, p, d, and f. (c) The magnetic quantum number gives the orientation of the orbital. For “s” orbitals there is one orientation, for “p” orbitals there are three orientations, for “d” orbitals there are five orientations, and for “f” orbitals there are seven orientations. (d) The spin quantum number gives the spin of an electron. There are two different values for the spin quantum number: +1/2 or –1/2. A positive spin quantum number is represented as an arrow pointing up and a negative spin quantum number is represented as an arrow pointing down. Each subshell of an orbital can hold two electrons of opposite spin. (2)(a) 2 (b) 6 (c) 2 (d) 1 (3)(a) n=1, l=0 (b) n=3, l=0 (c) n=2, l=1 (d) n=4, l=2 (e) n=5, l=3 (4)(a){0} (b) {-1,0,1} (c) {-2,-1,0,1,2} (d) {-3,-2,-1,0,1,2,3} (5) n=1, l=0, ml=0, ms=+1/2 or -1/2 (b) n=4, l=0, ml=0, ms=+1/2 or -1/2 (c) n=6, l=1, ml=-1, 0, or 1 (d) ms=+1/2 or -1/2 (6) 32 (4s = 2, 4p = 6, 4d = 10, 4f = 14 (7) (a) 1 (b) 4d (c) {-2, -1, 0, 1, 2} (d) 0, 1 (e) 0, 1, 2, 3 (f) 3 (3s, 3p, 3d) (g) 1 (3p) (h) 10 (i) 6 (j) 3p (k) 3 (8) (a) 3 (b) {-2, -1, 0, 1, 2} (c) 18 (d) 2 26
2-7. Define valence electrons and determine the number of valence electrons for an atom. 2-15. Give orbital notation for a given atom/ion. 2-16. Write electronic configuration for a given atom/ion. 2-17. Write noble gas configuration for a given atom/ion. 2-18. Recognize an excited state for a given element. Order of Filling Orbitals:
Atom
Atomic Number
Number of Electrons
Orbital Notation _____ 1s Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation _____ 1s Electron Configuration Noble Gas Configuration
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Atom
Atomic Number
Number of Electrons
Orbital Notation _____ _____ 1s 2s Electron Configuration Noble Gas Configuration Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
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Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration Electron Configuration Exceptions:
Excited States:
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WS #8 (Learning Targets 2.15, 2.16, 2.17, 2.18) Complete the following table:
Electron Configurations (1) State the number of electrons for each of the following elements and then give the orbital notation. (a) potassium
(b) cobalt
(c) selenium
(d) krypton
(e) tin
(f) yttrium
(g) neodymium
(h) californium
30
(2) State the number of electrons for each of the following elements and then give the electron configuration notation. (a) calcium
(e) tellurium
(b) iron
(f) indium
(c) germanium
(g) holmium
(d) rubidium
(h) fermium
(3) Give two possible excited states for each of the following elements. (a) hydrogen
(b) aluminum
(4) Give the noble gas notation for the following elements. (a) beryllium
(e) manganese
(i) plutonium
(b) scandium
(f) iodine
(j) copernicium
(c) silicon
(g) tantalum
(d) arsenic
(h) samarium
(5) Give the electron configuration for the following ions. (a) Mg2+
(b) Cl–
(c) Zr4+
(d) Bi3–
(6) Give the noble gas notation for the following ions. (a) Na+
(b) S2–
(c) Sr2+
(d) I–
31
Answers:
32
33
WS #9 (Unit 2 Review – part 1) 1.
(Learning Target 2-1) Identify the main contribution each of the following made to the development of the atomic theory. a. Dalton b. Thomson c. Rutherford d. Chadwick e. Bohr
2.
(Learning Target 2-3) Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom. Charge Proton Neutron Electron
3.
Relative Mass 1
Mass (amu)
Location
(2-2, 2-4) Complete the following table for NEUTRAL atoms.
Atomic Number
Element
Symbol
Atomic Mass
Protons
Electrons
Neutrons (Show Your Work)
Fluorine 36 Os 112 4.
(Learning Target 2-5) Among isotopes, which of the following are the same? Which are different? Atomic Number? Mass Number? Atomic Mass? # protons? # neutrons? # electrons?
5.
(Learning Target 2-6) Calculate the average atomic mass from the relative abundances and masses of each isotope.
There are four isotopes of lead: Lead–204 (1.4%), Lead–205 (24.1%), Lead–207 (22.1%), and Lead–208 (52.4%). (a) Determine the number of neutrons in each of the isotopes. Lead–204 = ________ Lead–205 = ________ Lead–207 = ________ Lead–208 = ________
(b) Determine the average atomic mass of Lead. Give the answer to one decimal place. Average atomic mass = _________
34
WS #9 (con’t) (Unit 2 Review – part 1) 6.
(Learning Target 2-7, 2-9, 2-10) Draw the Bohr diagram for the atom and the ion. Indicate the number of protons, electrons, and neutrons. Give the symbol and charge for the ion.
(a) boron ___ p ___ e ___ n symbol: ____ Atom:
7.
(b) chlorine ___ p ___ e ___ n symbol: ____
Ion:
Atom:
Ion:
(Learning Target 2-10) Complete the following table for IONS.
Atomic Number
Element
Symbol
Atomic Mass
Protons
Electrons (Show Your Work)
Neutrons (Show Your Work)
Beryllium 51 Lu3+ 210.1 8.
(Learning Target 2-8) Where are periods located on the Periodic Table? Groups? Families?
9.
(Learning Target 2-11) Distinguish between a cation and an anion.
10. (Learning Target 2-12) What is electromagnetic radiation? What is an example of electromagnetic radiation with a frequency below visible light? Above visible light? 11. (Learning Targets 2-13, 2-14)
(a) RADAR uses radiation with a wavelength of 58 mm; determine the frequency. frequency = __________________ (b) Gamma radiation from the decay of radioactive Plutonium has 1.5x1020 Hz; determine the wavelength. What is the energy of this form of radiation? wavelength = __________________ energy = __________________ (c) Long wave radio has a wavelength of 2.40 km; determine the frequency. What is the energy of this form of radiation? frequency = __________________ energy = __________________ 12. (Learning Target 2-15) Describe the experiment used to show the photoelectric effect and the significance of its findings. Define photon.
35
Answers: (1) (a) developed the atomic theory (b) discovered the electron in his cathode ray experiment, developed plum pudding model (c) discovered the nucleus in his gold-foil experiment (d) discovered the neutron (e) developed the orbital model of the atom (2) Proton Neutron Electron
Charge +1 0 -1
Relative Mass 1 1 1/1836
Mass (amu) 1 1 0
Location nucleus nucleus Outside of nucleus
(3) Atomic Number 9 36 76 112
Element Fluorine Krypton Osmium Copernicium
Symbol F Kr Os Cn
Atomic Mass
Protons
19.00 83.80 190.23 285
9 36 76 112
Electrons 9 36 76 112
Neutrons (Show Your Work) 10 48 190 – 76 = 114 4 – 112 = 173
(4) same atomic number, different mass number, different atomic mass, same # protons, different # neutrons, same # electrons (5) (a) 122, 123, 125, 126 (b) 207.0 amu (6) (a) 5p, 5e, 6n (b) 17p, 17e, 18n
(7) Atomic Number 4 51 71 85
Element
Symbol
Atomic Mass
Protons
Beryllium Antimony Lutetium Astatine
Be2+ Sb3Lu3+ At-
9.012 121.76 174.97 210.1
4 51 71 85
Electrons (Show Your Work) 4–2=2 51 + 3 = 54 71 – 3 = 68 85 + 1 = 86
Neutrons (Show Your Work) 5 71 104 125
(8) periods – horizontal rows, groups (aka families) – vertical columns (9) cation = positive ion, anion = negative ion (10) light waves; varies – below visible light = infrared, radio waves, microwaves; above visible light = ultraviolet, x-rays, gamma rays (11) (a) 5.2x109 Hz (b) 2.0x10–12 m, 9.9x10–14 J (c) 1.25x105 Hz; 8.28x10–29 J (12) Only light of a certain threshold frequency could eject electrons from metal. Showed that light has properties of particles. A photon is a particle, or packet, or electromagnetic energy.
36
WS #10 (Unit 2 Review – part 2) 1.
(Learning Target 2-16, 2-17) Quantum Numbers (a) Complete the following table. Symbol n l ml ms
Name
Definition
Possible values
(b) Complete the following table. l value
Orbital Letter
Orbital Shape
# orbitals per energy level
# electrons per orbital
Total # electrons per energy level
3
2
6
0
1
2
3
(c) Name the orbitals described by the following quantum numbers a. n = 3, L = 0 b. n = 3, L = 1 c. n = 3, L = 2 d. n = 5, L = 0 (d) Give the n and L values for the following orbitals. How many electrons can fit in each?) a. 1s b. 3s c. 2p d. 4d e. 5f (e) Which sets of quantum numbers are unacceptable? (Select a, b, c, or any combination) a. n=3, l= -2, ml= 0, ms= +½ b. n=2, l= 2, ml= -1, ms= -½ c. n=6, l= 2, ml= -2, ms= +½
37
WS #10 (con’t) (Unit 2 Review – part 2) 2.
(Learning Targets 2-18, 2-19, 2-20)
(i) Give the orbital notation for the following elements. (a) sodium
(b) iron
(c) europium
(ii) Give the electron configuration notation for the following elements. (a) neon
(b) bromine
(c) thallium
(iii) Give the electron configuration for two possible excited states for neon. (iv) Give the noble gas notation for the following elements. (a) fluorine
(b) titanium
(c) americium
(v) Give the electron configuration notation and noble gas notation for the following ions. (a) O2-
(b) Y3+
(vi) Give the noble gas configuration for the following elements. (a) chromium
(b) copper
Answers: (1)(a) Symbol n l ml ms
Name Principle quantum number Angular momentum quantum number Magnetic quantum number Magnetic spin quantum number
Definition Principle energy level Energy sublevel within the principle energy level Precise orbital within the sublevel Positive or negative spin of the electron
Possible values Any integer from 1 on up Any integer from 0 to n-1 Any integer from –l to +l +1/2 or -1/2
38
(1)(b) l value
Orbital Letter
0
Orbital Shape
# orbitals per energy level
# electrons per orbital
Total # electrons per energy level
s
1
2
2
1
p
3
2
6
2
d
5
2
10
3
f
7
2
14
(d) 3s, 3p, 3d, 5s (e) a. n=1, l=0, 2e b. n=3, l=0, 2e c. n=2, l=1, 6e d. n=4, l=2, 10e e. n=5, l=3, 14e (f) b only (2) (i)
(ii) (a) 1s2 2s2 2p6 (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 (c) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p1
(iii) answers will vary; Sample examples: 1s2 2s2 2p5 3s1 or 1s2 2s2 2p5 3p1 (iv) (a) [He] 2s2 2p5 (b) [Ar] 4s2 3d2 (c) [Rn] 7s2 5f7 (v) (a) 1s2 2s2 2p6 , [Ne] (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 , [Kr] (vi) (a) [Ar] 4s1 3d5 (b) [Ar] 4s1 3d10
39
1
2-1. Give the one main contribution to the development of the atomic model from each of the following scientists: Dalton, Thomson, Rutherford, Chadwick, and Bohr. Scientist
Experiment
Findings
Dalton
Thomson
Rutherford
Chadwick
Bohr
2
2-2. Identify elements by both name and chemical symbol using a periodic table. 2-3. Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom. 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element. Subatomic Particles Name
Symbol
Symbol
Name
24 11
𝑁𝑎
80 35
𝐵𝑟
40 20
𝐶𝑎
197 79
𝐴𝑢
16 8
𝑂2−
39 19
𝐾+
Charge
Relative Mass
Atomic Number
Mass Number
34
78
22
47
91
231
Number of Protons
Actual Mass (g)
Number of Neutrons
Location
Number of Electrons
3
WS #1 (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.
4
WS #1 (con’t) (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.
(11) Complete the following table for neutral atoms and/or ions. Substance
symbol
Magnesium
atomic number
mass number
12
24
Iron
S
Beryllium
16
Pt+3
Atom or ion?
atom 13
16
9
atom 24
194
U+2 Oxygen
number of electrons
24
13
24 Platinum
number of neutrons
12 26
26 Sulfur
number of protons
24 75
92
O2-
143 8
Gold 45
18
18
118
78
24 74
-1 ion
22 70
+2 ion
5
Substance
symbol
atomic number
mass number
number of protons
number of neutrons
number of electrons
Atom or ion?
Magnesium
Mg
12
24
12
12
12
atom
Iron
Fe
26
50
26
24
26
atom
Aluminum
Al
13
26
13
13
13
atom
Sulfur
S
16
32
16
16
16
Atom
Beryllium
Be
4
9
4
5
4
Atom
Chromium
Cr
24
48
24
24
24
Atom
Platinum
Pt+3
78
194
78
116
75
+3 ion
Uranium
U+2
92
235
92
143
90
+2 ion
Oxygen
O2-
8
16
8
8
10
-2 ion
Chlorine
Cl-
17
35
17
18
18
-1 ion
Gold
Au+
79
197
79
118
78
+1 ion
Chromium
Cr+2
24
45
24
21
22
+2 ion
Tungsten
W+2
74
144
74
70
72
+2 ion
6
2-5. Define isotope and state how the atomic structure for isotopes of the same element are similar and different. 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope. Isotopes are atoms of the _____________ _________________ that have _______________ numbers of ______________. Isotope
Carbon-12
Carbon-13
Carbon-14
Atomic Number
Mass Number
Number of Protons
Number of Neutrons
Mass Number is the number of ________________ and _________________ in an atom. Atomic Mass is the ______________________ _______________________ ___________________ of all the different isotopes of an element ____________________ by the abundance of each isotope in nature. Atomic mass is measured in Atomic Mass Units (_______) (1 amu = 1/12 the mass of a carbon-12 atom)
Example: Silver (atomic number 47) has two naturally occurring isotopes, Ag-107 and Ag-109. Given their atomic masses and percent abundances below, what is silver’s average atomic mass? Isotope
Mass (amu)
Abundance (%)
Ag-107
106.90509
51.84
Ag-109
108.90476
48.16
7
Example: Silicon (atomic number 14) has three naturally occurring isotopes, Si-28, Si-29 and Si-30. Given their atomic masses and percent abundances below, what is silicon’s average atomic mass? Isotope
Mass (amu)
Abundance (%)
Si-28
27.976927
92.23
Si-29
28.976495
4.67
Si-30
29.973770
3.10
8
WS #2 (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)
(1) Isotopes are different “versions” of the same atom that have the same number of _____________ but different numbers of _____________ and therefore different _____________ _____________. (2) How many neutrons does each isotope have? (a) Carbon-13
(b) Oxygen-18
(c) Potassium-40
(d) Scandium-45
(e) Manganese-55
(f) Tungsten-186
(3) There are two isotopes of copper: Copper-63 (69.17%) and Copper-65 (30.83%). (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of copper (round your answer to one decimal place).
(4) There are two isotopes of silver: Silver-107 (51.84%) and Silver-109 (48.16%). (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of silver (round your answer to one decimal place).
(5) There are three isotopes of magnesium: Magnesium-24 (78.7%), Magnesium-25 (10.1%), and Magnesium-26 (11.2%) (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of magnesium (round your answer to one decimal place).
(6) There are four isotopes of iron: Iron-54 (5.85%), Iron-56 (91.75%), Iron-57 (2.12%), and Iron-58 (0.28%) (a) Determine the number of neutrons in each of the isotopes. (b) Calculate the average atomic mass of iron (round your answer to one decimal place).
(7) There are two isotopes of gallium: Gallium-69 and Gallium-71. (a) Determine the number of neutrons in each of the isotopes. (b) Gallium-69 has an abundance of 60.11%, what is the abundance of Gallium-71? (c) Calculate the average atomic mass of gallium (round your answer to one decimal place).
9
WS #2 (con’t) (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)
(8) There are two isotopes of bromine: Bromine-79 and Bromine-81. (a) Determine the number of neutrons in each of the isotopes. (b) Bromine-79 has an abundance of 50.69%, what is the abundance of Bromine-81? (c) Calculate the average atomic mass of bromine (round your answer to one decimal place).
(9) There are five isotopes of germanium: Germanium-70, Germanium-72, Germanium-73, Germanium-74, and Germanium-76 (a) Determine the number of neutrons in each of the isotopes. (b) Germanium-70 has an abundance of 21.23%, Germanium-72 has an abundance of 27.66%, Germanium-73 has an abundance of 7.73%, and Germanium-74 has an abundance of 35.94%. What is the abundance of Germanium-76? (c) Calculate the average atomic mass of germanium (round your answer to one decimal place).
(10) There are four isotopes of strontium: Strontium-84, Stronium-86, Strontium-87, and Strontium-88. (a) Determine the number of neutrons in each of the isotopes. (b) Strontium-84 has an abundance of 0.56%, Strontium-86 has an abundance of 9.86%, and Strontium-87 has an abundance of 7.00%. What is the abundance of Strontium-88? (c) Calculate the average atomic mass of strontium (round your answer to one decimal place).
Answers: Isotopes (1) Isotopes are different “versions” of the same atom that have the same number of protons but different numbers of neutrons and therefore different atomic masses (2) (a) 7 (b) 10 (c) 21 (d) 24 (e) 30 (f) 112 . (3) (a) 34, 36 (b) 63.6 amu (4) (a) 60, 62 (b) 108.0 amu (5) (a) 12, 13, 14 (b) 24.3 amu (6) (a) 28, 30, 31, 32 (b) 55.9 amu (7) (a) 38, 40 (b) 39.89% (c) 69.8 amu (8) (a) 44, 46 (b) 49.31% (c) 80.0 amu (9) (a) 38, 40, 41, 42, 44 (b) 7.44% (c) 72.67 amu (10) (a) 46, 48, 49, 50 (b) 82.58% (c) 87.7 amu 10
2-7. Define valence electrons and determine the number of valence electrons for an atom. 2-8. Locate rows/periods and groups/families on the periodic table. 2-9. Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion.
Periods on the periodic table go ______________ and __________________. Groups on the periodic table go ______________ and __________________. Valence Electrons =
How to determine the number of valence electrons an atom has:
Sample Problem. How many valence electrons? Carbon Magnesium Chlorine Helium
11
WS #3 (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
12
13
WS #4 (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
14
WS #4 (con’t) (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the atom resembles once it forms an ion. )
15
2-12. Define and give examples of electromagnetic radiation. 2-13. Define wavelength and frequency and state the units used to measure each quantity. 2-14. Perform calculations involving wavelength, frequency, and energy, giving answers with the appropriate units and significant figures.
All waves of the _____________________ _________________________ travel at the ________________ _____ ________________, approximately c = 3.00 x 108 m/s The relationship between wave speed, wavelength and frequency is given by the equation:
𝑐 = 𝜈𝜆 c = speed of light 3.00 x 108 m/s 𝜈 = frequency (in s-1 or Hz) 𝜆 = wavelength (m)
The greater the frequency, the _______________ the wavelength. The lower the frequency, the ________________ the wavelength. Wavelength and frequency are __________________ proportional.
Sample Problem. A certain photon of light has a wavelength of 422 nm. What is the frequency of the light?
16
Sample Problem. What is the wavelength of a photon of light whose frequency is 5.0 x 1015 Hz ?
Energy and Frequency
𝐸 = ℎ𝜈 E = Energy (J) h = Planck’s constant, 6.626 x 10-34 Js 𝜈 = Frequency
Sample Problem. A certain green light has a frequency of 6.26 x 1014 Hz. What is the energy of one photon of this light?
Sample Problem. A certain source emits radiation of wavelength 500.0 nm. What is the energy, in J, of one of its photons?
17
WS #5 (Learning Targets 2.12. Define and give examples of electromagnetic radiation. 2.13. Define wavelength and frequency and state the units used to measure each quantity. 2.14. Perform calculations involving wavelength, frequency, and energy, giving answers with the appropriate units and significant figures. )
Answer the following questions in the space provided. For any calculation, give the equation used to solve the problem and answer with appropriate units and significant figures.
(1) Wavelength is written using the variable ______ which has a symbol of ____ and units of _________ which are given the symbol ____. (2) Frequency is written using the variable ______ which has a symbol of ____ and units of _________ which are given the symbol ____. (3) The speed is light is written using the variable ______ and is equal to __________________. (4) The higher the frequency, the _______________ the wavelength. The lower the frequency, the _______________the wavelength. (5) Which has a longer wavelength˗ gamma rays or microwaves? (6) Which has a higher frequency˗ ultraviolet or infrared radiation? (7) A microwave has a frequency of 4.0x1010 Hz. Determine the wavelength.
λ = ____________________
(8) A gamma ray has a wavelength of 2.40x10˗12 m. Determine the frequency.
ν = ____________________
(9) Infrared radiation has a frequency of 8.40x1013 Hz. Determine the wavelength.
λ = ____________________
(10) A radiowave has a wavelength of 20.5 m. Determine the frequency.
ν = ____________________
(11) A radio wave has a frequency of 91.5 MHz. Determine the wavelength.
λ = ____________________
(12) The color violet can have a wavelength of 390 nm. Determine the frequency.
ν = ____________________
18
WS #5 (Con’t) (13) Albert Einstein proposed that light is a stream of particles called _______________. _______________ have a specific energy depending on their wavelength/frequency and can be thought of as massless “packets of _______________”. Einstein proposed this idea to explain the results of the __________________ effect experiment. In this experiment, light of a specific wavelength/frequency is shined on the surface of a _______________. If the light has enough energy the _______________ will “knock” _______________ off the surface of the _______________. If the light does not have a _______________ enough energy, even if it is shined on a metal for an extended period of time, no _______________ will be emitted. Each metal has a specific amount of energy required to emit electrons. (14) Energy has units of __________ which are given the symbol ______. (15) Electromagnetic radiation with a high energy has a __________ wavelength and a __________ frequency. Electromagnetic radiation with a low energy has a __________ wavelength and a __________ frequency. (16) Which is higher in energy˗ radio waves or visible light? (17) Which is lower in energy˗ X˗rays or radiowaves? (18) Calculate the energy of light with a frequency of 8.4x1020 Hz.
E = ____________________
(19) Calculate the energy of light with a wavelength of 2.50x10˗7 m.
E = ____________________
(20) The laser in a CD player uses light with a frequency of 3.85x1014 Hz. Determine the wavelength of the light from the laser. Calculate the energy of a photon with this frequency. λ = ____________________ E = ____________________ (21) Excessive exposure to ultraviolet light can cause skin cancer and retinal damage. Damaging ultraviolet light has a wavelength of 1.5x10˗9 m. Determine the frequency of UV light. Calculate the energy of a photon with this wavelength. ν = ____________________ E = ____________________ (22) It takes 7.21 x 10–19 J of energy to remove an electron from an iron atom. Determine the frequency and wavelength of a photon of light that could accomplish this. ν = ____________________ λ = ____________________
Answers: (1) Wavelength is written using the variable lambda which has a symbol of λ and units of meters which are given the symbol m. (2) Frequency is written using the variable nu which has a symbol of ν and units of Hertz which are given the symbol Hz. (3) The speed is light is written using the variable c and is equal to 3.00x108 m/s. (4) The higher the frequency, the lower the wavelength. The lower the frequency, the higher the wavelength. (5) microwaves (6) ultraviolet (7) 7.5x10˗3 m (8) 1.25x1020 Hz (9) 3.57x10˗6 m (10) 1.46x107 Hz (11) 3.28 m (12) 7.69x1014 Hz (13) Albert Einstein proposed that light is a stream of particles called photons. Photons have a specific energy depending on their wavelength/frequency and can be thought of as massless “packets of energy”. Einstein proposed this idea to explain the results of the photoelectric effect experiment. In this experiment, light of a specific wavelength/frequency is shined on the surface of a metal. If the light has enough energy the photons will “knock” electrons off the surface of the metal. If the light does not have a high enough energy, even if it is shined on a metal for an extended period of time, no electrons will be emitted. Each metal has a specific amount of energy required to emit electrons. (14) Energy is has units of Joules which are given the symbol J. (15) Electromagnetic radiation with a high energy has a low wavelength and a high frequency. Electromagnetic radiation with a low energy has a high wavelength and a low frequency. (16) visible light (17) radio waves (18) 5.6x10˗13 J (19) 7.95x10˗19 J (20) 7.79x10˗7 m, 2.55x10˗19 J (2) 2.0x1017 Hz, 1.3x10˗16 J (22) 1.09x1015 Hz, 2.76x10˗7 m 19
2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. Two problems with Bohr’s Orbital Model of the atom are: 1.
2. The photoelectric effect showed that light behaves like particles, because only light with a certain _______________ _________________ can eject electrons from a metal’s surface. That light is only given off in discrete packets of energy gives it characteristics of a ____________________. This particle is called a ___________________. A photon is a discrete bundle (or __________________) of electromagnetic (light) energy that travels at the speed of light. Therefore, whereas light is a wave of electromagnetic energy, it also behaves as a particle, a photon. Physicists, in attempting to apply Bohr’s orbital model to more complex atoms, deduced that particles as small as atoms and electrons could not be explained by the classical mechanics of Newton. They began to see a ________________ _________________ to electrons, as well as light – sometimes electrons behaved as __________________; sometimes as ____________________. The _____________________ _____________________ _____________________ shows that, when electrons are shot through two slits, they make an interference pattern like a ____________________, not a _______________________. Standing waves form when two traveling waves traveling in opposite directions at the same speed combine or run into each other. Since only certain standing waves will fit perfectly inside an atom, electrons trapped in that atom can only have certain electron ____________________ _____________________ with certain electron _________________________. This explains the quantization of energy. Schrodinger was the first person to write down a wave equation to describe the ________________ ______________________ of _____________________. It describes the __________________ of finding an electron at any point in time. Heisenberg Uncertainty Principle – it is impossible to know both the exact __________________ and _______________________ of a particle at the same time. Significance: We _________________ ___________________ ______________________ where to find an electron in an atom. Rather, we talk about _________________________ of finding an electron. Schrodinger’s equation, then, was used to find the ____________________ ____________________ __________________ of electrons and its associated _______________________ gives the _________________________ of finding the electron at a certain position. _____________________ _______________________ are the specific solutions to Schrodinger’s Equation…
20
WS #6 (Learning Target 2:16: Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. ) 1.
Light acts as both a ___________________ and a ______________________.
2.
Light is absorbed and emitted in discrete packets of _____________________ known as ____________________ which describes the emission spectrum of atoms.
3.
Electrons ALSO act as both ___________________ and a ______________________.
4.
Evidence for this is the ____________________ _______________________ experiment.
5.
In the ____________________ _______________________ experiment, electrons are shot at two slits, and form ___________________________ patterns like waves.
6.
Electrons act as _______________________ waves around the nucleus.
7.
___________________ __________________ ___________________ says that you cannot know the __________________ and _______________________ of an electron at the same time.
8.
Therefore, we talk about the _____________________ of finding an electron.
9.
_______________________ developed a _________________ equation to describe the wave nature of electrons.
10. It also describes the _______________________ of finding an electron at any point in time.
Answers: (1) wave, particle (any order) (2) energy, photons (3) particles, waves (any order) (4) double slit (5) double slit, interference (6) standing (7) Heisenberg’s Uncertainty Principle, position, momentum (8) probability (9) Schrodinger, wave (1) probability
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2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define. Three Important Rules: Pauli Exclusion Principle: No two electrons in an atom can have the same ____________ _____________________ __________________. Aufbau Principle: Fill from the ______________ energy level _______________. Hund's Rule: If multiple orbitals have the same energy, electrons _________________ _____________ before _________________ _________. Define the following. Type Principle Quantum Number
Symbol n
Angular Momentum Quantum Number
l
Magnetic Quantum Number
ml
Spin Quantum Number
ms
Definition
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Principle Quantum Number (n) Possible Values
Angular Momentum Quantum Number (l)
Magnetic Quantum Number (ml)
Magnetic Spin Quantum Number (ms)
Electron Configuration
Max # Electrons
Orbital Name and Shape
1
2
3
4
5
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2-14. List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold. Angular Momentum Quantum Number (l)
Orbital Letter
Orbital Shape
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WS #7 (Learning Targets 2.14: List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold and 2-16. Discuss the quantum numbers: principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number and the properties they define.)
1. Fill in the blanks. (a) The principle quantum number describes the _____________ level of an orbital and is given the letter designation n. The higher the principle quantum number, the _______________ the energy level of the orbital and the ____________ the size of the orbital. (b) The angular momentum number describes the ______________ of an orbital. Each shape is given a letter designation. There are four letter designations for orbitals: ____, _____, ______ and _____. (c) The magnetic quantum number gives the ________________ of the orbital. For “s” orbitals there is ________ orientation, for “p” orbitals there are ______________ orientations, for “d” orbitals there are _____________ orientations, and for “f” orbitals there are ______________ orientations. (d) The spin quantum number gives the spin of an ________________. There are two different values for the spin quantum number: ____________ or __________. A positive spin quantum number is represented as an arrow pointing ___________ and a negative spin quantum number is represented as an arrow pointing __________. Each subshell of an orbital can hold two electrons of opposite spin. 2. State the number of possible electrons described by the following quantum numbers a. n = 3, l = 0 b. n = 3, l = 1 c. n = 3, l = 2, ml = -1 d. n = 5, l = 0, ml -2, ms -1/2 3. Give the n and l values for the following orbitals a. 1s b. 3s c. 2p d. 4d e. 5f 4. What is the ml values for the following types of orbitals? a. s b. p c. d d. f 5. Write the complete set of quantum numbers that represent a valence electron for the following elements: a. He b. Ca c. At
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6. How many electrons can inhabit all of the n=4 orbitals? 7. Fill in the blanks with the correct response: a. b. c. d. e. f. g. h. i. j. k. 8.
The number of orbitals with the quantum numbers n=3, l=2 and ml = 0 is _________. The subshell with the quantum numbers n=4, l=2 is _________. The ml values for a d orbital are ________________________. The allowed values of l for the shell with n=2 are _________. The allowed values of l for the shell with n=4 are _________. The number of orbitals in a shell with n=3 is _________. The number of orbitals with n=3 and l=1 is _________. The maximum number of electrons with quantum numbers with n=3 and l=2 is _________. The number of electrons with n=4, l=1 is _________. The subshell with n=3 and l=1 is designated as the __________ subshell. The lowest value of n for which a d subshell can occur is n=_________. a. What is the value of l for a 4 f electron? b. What are the possible values of ml for a 5d electron? c. What is the maximum number of electrons in the 3rd energy level? d. How many electrons have the following quantum numbers: n =4, l = 2, ml = -2?
Answers. (1) (a) The principle quantum number describes the energy level of an orbital and is given the letter designation n. The higher the principle quantum number, the higher the energy level of the orbital and the larger the size of the orbital. (b) The angular momentum number describes the shape of an orbital. Each shape is given a letter designation. There are four letter designations for orbitals: s, p, d, and f. (c) The magnetic quantum number gives the orientation of the orbital. For “s” orbitals there is one orientation, for “p” orbitals there are three orientations, for “d” orbitals there are five orientations, and for “f” orbitals there are seven orientations. (d) The spin quantum number gives the spin of an electron. There are two different values for the spin quantum number: +1/2 or –1/2. A positive spin quantum number is represented as an arrow pointing up and a negative spin quantum number is represented as an arrow pointing down. Each subshell of an orbital can hold two electrons of opposite spin. (2)(a) 2 (b) 6 (c) 2 (d) 1 (3)(a) n=1, l=0 (b) n=3, l=0 (c) n=2, l=1 (d) n=4, l=2 (e) n=5, l=3 (4)(a){0} (b) {-1,0,1} (c) {-2,-1,0,1,2} (d) {-3,-2,-1,0,1,2,3} (5) n=1, l=0, ml=0, ms=+1/2 or -1/2 (b) n=4, l=0, ml=0, ms=+1/2 or -1/2 (c) n=6, l=1, ml=-1, 0, or 1 (d) ms=+1/2 or -1/2 (6) 32 (4s = 2, 4p = 6, 4d = 10, 4f = 14 (7) (a) 1 (b) 4d (c) {-2, -1, 0, 1, 2} (d) 0, 1 (e) 0, 1, 2, 3 (f) 3 (3s, 3p, 3d) (g) 1 (3p) (h) 10 (i) 6 (j) 3p (k) 3 (8) (a) 3 (b) {-2, -1, 0, 1, 2} (c) 18 (d) 2 26
2-7. Define valence electrons and determine the number of valence electrons for an atom. 2-15. Give orbital notation for a given atom/ion. 2-16. Write electronic configuration for a given atom/ion. 2-17. Write noble gas configuration for a given atom/ion. 2-18. Recognize an excited state for a given element. Order of Filling Orbitals:
Atom
Atomic Number
Number of Electrons
Orbital Notation _____ 1s Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation _____ 1s Electron Configuration Noble Gas Configuration
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Atom
Atomic Number
Number of Electrons
Orbital Notation _____ _____ 1s 2s Electron Configuration Noble Gas Configuration Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
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Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration
Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration Atom
Atomic Number
Number of Electrons
Orbital Notation
Electron Configuration Noble Gas Configuration Electron Configuration Exceptions:
Excited States:
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WS #8 (Learning Targets 2.15, 2.16, 2.17, 2.18) Complete the following table:
Electron Configurations (1) State the number of electrons for each of the following elements and then give the orbital notation. (a) potassium
(b) cobalt
(c) selenium
(d) krypton
(e) tin
(f) yttrium
(g) neodymium
(h) californium
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(2) State the number of electrons for each of the following elements and then give the electron configuration notation. (a) calcium
(e) tellurium
(b) iron
(f) indium
(c) germanium
(g) holmium
(d) rubidium
(h) fermium
(3) Give two possible excited states for each of the following elements. (a) hydrogen
(b) aluminum
(4) Give the noble gas notation for the following elements. (a) beryllium
(e) manganese
(i) plutonium
(b) scandium
(f) iodine
(j) copernicium
(c) silicon
(g) tantalum
(d) arsenic
(h) samarium
(5) Give the electron configuration for the following ions. (a) Mg2+
(b) Cl–
(c) Zr4+
(d) Bi3–
(6) Give the noble gas notation for the following ions. (a) Na+
(b) S2–
(c) Sr2+
(d) I–
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Answers:
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WS #9 (Unit 2 Review – part 1) 1.
(Learning Target 2-1) Identify the main contribution each of the following made to the development of the atomic theory. a. Dalton b. Thomson c. Rutherford d. Chadwick e. Bohr
2.
(Learning Target 2-3) Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom. Charge Proton Neutron Electron
3.
Relative Mass 1
Mass (amu)
Location
(2-2, 2-4) Complete the following table for NEUTRAL atoms.
Atomic Number
Element
Symbol
Atomic Mass
Protons
Electrons
Neutrons (Show Your Work)
Fluorine 36 Os 112 4.
(Learning Target 2-5) Among isotopes, which of the following are the same? Which are different? Atomic Number? Mass Number? Atomic Mass? # protons? # neutrons? # electrons?
5.
(Learning Target 2-6) Calculate the average atomic mass from the relative abundances and masses of each isotope.
There are four isotopes of lead: Lead–204 (1.4%), Lead–205 (24.1%), Lead–207 (22.1%), and Lead–208 (52.4%). (a) Determine the number of neutrons in each of the isotopes. Lead–204 = ________ Lead–205 = ________ Lead–207 = ________ Lead–208 = ________
(b) Determine the average atomic mass of Lead. Give the answer to one decimal place. Average atomic mass = _________
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WS #9 (con’t) (Unit 2 Review – part 1) 6.
(Learning Target 2-7, 2-9, 2-10) Draw the Bohr diagram for the atom and the ion. Indicate the number of protons, electrons, and neutrons. Give the symbol and charge for the ion.
(a) boron ___ p ___ e ___ n symbol: ____ Atom:
7.
(b) chlorine ___ p ___ e ___ n symbol: ____
Ion:
Atom:
Ion:
(Learning Target 2-10) Complete the following table for IONS.
Atomic Number
Element
Symbol
Atomic Mass
Protons
Electrons (Show Your Work)
Neutrons (Show Your Work)
Beryllium 51 Lu3+ 210.1 8.
(Learning Target 2-8) Where are periods located on the Periodic Table? Groups? Families?
9.
(Learning Target 2-11) Distinguish between a cation and an anion.
10. (Learning Target 2-12) What is electromagnetic radiation? What is an example of electromagnetic radiation with a frequency below visible light? Above visible light? 11. (Learning Targets 2-13, 2-14)
(a) RADAR uses radiation with a wavelength of 58 mm; determine the frequency. frequency = __________________ (b) Gamma radiation from the decay of radioactive Plutonium has 1.5x1020 Hz; determine the wavelength. What is the energy of this form of radiation? wavelength = __________________ energy = __________________ (c) Long wave radio has a wavelength of 2.40 km; determine the frequency. What is the energy of this form of radiation? frequency = __________________ energy = __________________ 12. (Learning Target 2-15) Describe the experiment used to show the photoelectric effect and the significance of its findings. Define photon.
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Answers: (1) (a) developed the atomic theory (b) discovered the electron in his cathode ray experiment, developed plum pudding model (c) discovered the nucleus in his gold-foil experiment (d) discovered the neutron (e) developed the orbital model of the atom (2) Proton Neutron Electron
Charge +1 0 -1
Relative Mass 1 1 1/1836
Mass (amu) 1 1 0
Location nucleus nucleus Outside of nucleus
(3) Atomic Number 9 36 76 112
Element Fluorine Krypton Osmium Copernicium
Symbol F Kr Os Cn
Atomic Mass
Protons
19.00 83.80 190.23 285
9 36 76 112
Electrons 9 36 76 112
Neutrons (Show Your Work) 10 48 190 – 76 = 114 4 – 112 = 173
(4) same atomic number, different mass number, different atomic mass, same # protons, different # neutrons, same # electrons (5) (a) 122, 123, 125, 126 (b) 207.0 amu (6) (a) 5p, 5e, 6n (b) 17p, 17e, 18n
(7) Atomic Number 4 51 71 85
Element
Symbol
Atomic Mass
Protons
Beryllium Antimony Lutetium Astatine
Be2+ Sb3Lu3+ At-
9.012 121.76 174.97 210.1
4 51 71 85
Electrons (Show Your Work) 4–2=2 51 + 3 = 54 71 – 3 = 68 85 + 1 = 86
Neutrons (Show Your Work) 5 71 104 125
(8) periods – horizontal rows, groups (aka families) – vertical columns (9) cation = positive ion, anion = negative ion (10) light waves; varies – below visible light = infrared, radio waves, microwaves; above visible light = ultraviolet, x-rays, gamma rays (11) (a) 5.2x109 Hz (b) 2.0x10–12 m, 9.9x10–14 J (c) 1.25x105 Hz; 8.28x10–29 J (12) Only light of a certain threshold frequency could eject electrons from metal. Showed that light has properties of particles. A photon is a particle, or packet, or electromagnetic energy.
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WS #10 (Unit 2 Review – part 2) 1.
(Learning Target 2-16, 2-17) Quantum Numbers (a) Complete the following table. Symbol n l ml ms
Name
Definition
Possible values
(b) Complete the following table. l value
Orbital Letter
Orbital Shape
# orbitals per energy level
# electrons per orbital
Total # electrons per energy level
3
2
6
0
1
2
3
(c) Name the orbitals described by the following quantum numbers a. n = 3, L = 0 b. n = 3, L = 1 c. n = 3, L = 2 d. n = 5, L = 0 (d) Give the n and L values for the following orbitals. How many electrons can fit in each?) a. 1s b. 3s c. 2p d. 4d e. 5f (e) Which sets of quantum numbers are unacceptable? (Select a, b, c, or any combination) a. n=3, l= -2, ml= 0, ms= +½ b. n=2, l= 2, ml= -1, ms= -½ c. n=6, l= 2, ml= -2, ms= +½
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WS #10 (con’t) (Unit 2 Review – part 2) 2.
(Learning Targets 2-18, 2-19, 2-20)
(i) Give the orbital notation for the following elements. (a) sodium
(b) iron
(c) europium
(ii) Give the electron configuration notation for the following elements. (a) neon
(b) bromine
(c) thallium
(iii) Give the electron configuration for two possible excited states for neon. (iv) Give the noble gas notation for the following elements. (a) fluorine
(b) titanium
(c) americium
(v) Give the electron configuration notation and noble gas notation for the following ions. (a) O2-
(b) Y3+
(vi) Give the noble gas configuration for the following elements. (a) chromium
(b) copper
Answers: (1)(a) Symbol n l ml ms
Name Principle quantum number Angular momentum quantum number Magnetic quantum number Magnetic spin quantum number
Definition Principle energy level Energy sublevel within the principle energy level Precise orbital within the sublevel Positive or negative spin of the electron
Possible values Any integer from 1 on up Any integer from 0 to n-1 Any integer from –l to +l +1/2 or -1/2
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(1)(b) l value
Orbital Letter
0
Orbital Shape
# orbitals per energy level
# electrons per orbital
Total # electrons per energy level
s
1
2
2
1
p
3
2
6
2
d
5
2
10
3
f
7
2
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(d) 3s, 3p, 3d, 5s (e) a. n=1, l=0, 2e b. n=3, l=0, 2e c. n=2, l=1, 6e d. n=4, l=2, 10e e. n=5, l=3, 14e (f) b only (2) (i)
(ii) (a) 1s2 2s2 2p6 (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 (c) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p1
(iii) answers will vary; Sample examples: 1s2 2s2 2p5 3s1 or 1s2 2s2 2p5 3p1 (iv) (a) [He] 2s2 2p5 (b) [Ar] 4s2 3d2 (c) [Rn] 7s2 5f7 (v) (a) 1s2 2s2 2p6 , [Ne] (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 , [Kr] (vi) (a) [Ar] 4s1 3d5 (b) [Ar] 4s1 3d10
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