Unit One: Chemical Reactions
1st Prep. Science
2nd Term
Unit One: Chemical Reactions Lesson Two: Chemical Compounds Sheet (09) 1. Complete the following statements: 1. The valency of hydrogen [1H1] atom is ____________, while the valency of oxygen [8O16] atom is ____________. 2. The symbol of sulphate group is ____________ and it is formed of ____________ atoms of ____________ different elements. 3. ____________ and ____________ are examples of bases. 4. The symbols of all mineral acids begin with ____________ atom, while the symbols of all bases end by ____________ group. 5. The valency is the number of electrons which ____________, ____________ or shared by an atom during chemical reaction. 2. Choose the correct answer: 1. All the following elements are monovalent except ____________. a. Hydrogen. b. Sodium. c. Oxygen. d. Chlorine. 2. The atomic group that is formed of the same elements of water is ____________. a. Carbonate. b. Hydroxide. c. Sulphate. d. Nitrate. 3. Element [M] form a compound (OH)3 so, its valency is ____________. a. Monovalent. b. Divalent. c. Trivalent. d. Tetravalent. 4. When an acid dissolves in water, it produces ____________ ions. a. OH+. b. H-. c. H+. d. OH-. 5. The salt that is formed on combination of a positive atomic group with a negative atomic group is ____________. a. NH4Cl. b. (NH4)2CO3. c. Na2SO4. d. NH4Br. 3. Write the scientific term for each of the following: 1. A set of atoms joined together, behave like one atom only, having a special valency and can’t be existed solely. 2. Compounds dissolved [dissociated] in water producing positive hydrogen ions [H+]. 3. Substances are dissociated in water producing negative hydroxide ions [OH-]. 4. Oxides produced due to the combination of oxygen with a metal.
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1st Prep. Science
2nd Term
4. Put ( ) or ( ), then correct what is wrong: 1. The valency of Nobel gases is monovalent. 2. The chemical formula of aluminium sulphate is Al3(SO4)2. 3. Table salt is formed of two divalent elements. 4. Calcium is a metal oxide, while carbon dioxide is a nonmetal oxide. 5. An element of atomic number 20, so its valency is divalent. 5. Give reasons for: 1. Magnesium [12Mg] is divalent, while aluminium [13Al] is trivalent. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 2. An oxygen atom joins two atoms of sodium when composing one molecule of sodium oxide. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 3. All acids turn the colour of litmus to be red and having a sour taste, while all bases turn the colour of litmus to be blue with a slippery taste. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 6. You have three tubes as the figure: 1. Write the chemical formula of each one. ___________________________________________________________________________________________ 2. Identify the type of each of them. ___________________________________________________________________________________________ 3. What is the effect of putting blue litmus paper on tubes (2) and (3)? ___________________________________________________________________________________________ 4. What happens by adding water to tube (1) with shaking? ___________________________________________________________________________________________
7. Write the chemical formula of the following compounds: 1. Nitric acid. ___________________________________________________________________________________________ 2. Calcium nitrate. ___________________________________________________________________________________________ 3. Potassium sulphate. ___________________________________________________________________________________________ 4. Potassium carbonate. ___________________________________________________________________________________________
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2nd Term
Unit One: Chemical Reactions Lesson Two: Chemical Compounds Sheet (09) 1. Complete the following statements: 1. The valency of hydrogen [1H1] atom is ____________, while the valency of oxygen [8O16] atom is ____________. 2. The symbol of sulphate group is ____________ and it is formed of ____________ atoms of ____________ different elements. 3. ____________ and ____________ are examples of bases. 4. The symbols of all mineral acids begin with ____________ atom, while the symbols of all bases end by ____________ group. 5. The valency is the number of electrons which ____________, ____________ or shared by an atom during chemical reaction. 2. Choose the correct answer: 1. All the following elements are monovalent except ____________. a. Hydrogen. b. Sodium. c. Oxygen. d. Chlorine. 2. The atomic group that is formed of the same elements of water is ____________. a. Carbonate. b. Hydroxide. c. Sulphate. d. Nitrate. 3. Element [M] form a compound (OH)3 so, its valency is ____________. a. Monovalent. b. Divalent. c. Trivalent. d. Tetravalent. 4. When an acid dissolves in water, it produces ____________ ions. a. OH+. b. H-. c. H+. d. OH-. 5. The salt that is formed on combination of a positive atomic group with a negative atomic group is ____________. a. NH4Cl. b. (NH4)2CO3. c. Na2SO4. d. NH4Br. 3. Write the scientific term for each of the following: 1. A set of atoms joined together, behave like one atom only, having a special valency and can’t be existed solely. 2. Compounds dissolved [dissociated] in water producing positive hydrogen ions [H+]. 3. Substances are dissociated in water producing negative hydroxide ions [OH-]. 4. Oxides produced due to the combination of oxygen with a metal.
1
1st Prep. Science
2nd Term
4. Put ( ) or ( ), then correct what is wrong: 1. The valency of Nobel gases is monovalent. 2. The chemical formula of aluminium sulphate is Al3(SO4)2. 3. Table salt is formed of two divalent elements. 4. Calcium is a metal oxide, while carbon dioxide is a nonmetal oxide. 5. An element of atomic number 20, so its valency is divalent. 5. Give reasons for: 1. Magnesium [12Mg] is divalent, while aluminium [13Al] is trivalent. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 2. An oxygen atom joins two atoms of sodium when composing one molecule of sodium oxide. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 3. All acids turn the colour of litmus to be red and having a sour taste, while all bases turn the colour of litmus to be blue with a slippery taste. ___________________________________________________________________________________________ ___________________________________________________________________________________________ 6. You have three tubes as the figure: 1. Write the chemical formula of each one. ___________________________________________________________________________________________ 2. Identify the type of each of them. ___________________________________________________________________________________________ 3. What is the effect of putting blue litmus paper on tubes (2) and (3)? ___________________________________________________________________________________________ 4. What happens by adding water to tube (1) with shaking? ___________________________________________________________________________________________
7. Write the chemical formula of the following compounds: 1. Nitric acid. ___________________________________________________________________________________________ 2. Calcium nitrate. ___________________________________________________________________________________________ 3. Potassium sulphate. ___________________________________________________________________________________________ 4. Potassium carbonate. ___________________________________________________________________________________________
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