o Positive charge ⢠Electrons
Chemistry 1A Week 1 Lecture Notes Atom ·
· ·
· ·
Nucleus o Protons (+), neutrons (o) o Positive charge Electrons (-) Subatomic particles (protons, neutrons, electrons) o Measured in atomic mass units (u) o Neutral atom: protons = electrons Overall mass made of protons + neutrons (mass of electrons is insignificant) Overall volume/size made of protons, neutrons & electrons
Molecule ·
Collection of atoms chemically bonded & uncharged
Element · · ·
Collection of one type of atom Defined by number of protons Represented by chemical symbol:
Where A = Mass No, Z = Atomic No, C+/- = charge Ion · · ·
Atoms that have gained or lost electrons Gained electrons: Charge is negative (anion) Lost electrons: Charge is positive (cation)
Isotope · · · ·
Atom with different number of protons and neutrons Heavier isotopes occur in natural abundances Atomic mass (u) = average mass of atoms of isotopes as the occur naturally To calculate: o Divide percentages by 100 to find natural abundances o Atomic mass = (abundance 1 x mass 1) + (abundance 2 x mass 2)
· ·
· ·
Nucleus o Protons (+), neutrons (o) o Positive charge Electrons (-) Subatomic particles (protons, neutrons, electrons) o Measured in atomic mass units (u) o Neutral atom: protons = electrons Overall mass made of protons + neutrons (mass of electrons is insignificant) Overall volume/size made of protons, neutrons & electrons
Molecule ·
Collection of atoms chemically bonded & uncharged
Element · · ·
Collection of one type of atom Defined by number of protons Represented by chemical symbol:
Where A = Mass No, Z = Atomic No, C+/- = charge Ion · · ·
Atoms that have gained or lost electrons Gained electrons: Charge is negative (anion) Lost electrons: Charge is positive (cation)
Isotope · · · ·
Atom with different number of protons and neutrons Heavier isotopes occur in natural abundances Atomic mass (u) = average mass of atoms of isotopes as the occur naturally To calculate: o Divide percentages by 100 to find natural abundances o Atomic mass = (abundance 1 x mass 1) + (abundance 2 x mass 2)
