The chemical properties of an element depend on

1.   ?    its relative atomic mass
2.   ?    the number of isotopes of the element
3.   ?    the number of electron shells in its atoms
4.   ?    the number of outermost shell electrons in its atoms

Argon exists as a gas at room temperature and pressure beacuse

1.   ?    argon molecules are monoatomic
2.   ?    argon is chemically inert
3.   ?    the outermost electron shell of an argon atom has an octet structure
4.   ?    the attractive force between argon atoms is weak

The mass number of atom X is 27, X forms a cation with a charge of +3. if the number of neutrons in the cation is 14, what is the number of electrons in the cation?

1.   ?    10
2.   ?    13
3.   ?    14
4.   ?    17

Which of the following elements can react together to form a covalent compound?
(1) argon
(2) nitrogen
(3) oxygen
(4) calcium

1.   ?    (1) and (2) only
2.   ?    (1) and (4) only
3.   ?    (2) and (3) only
4.   ?    (3) and (4) only

Which of the following correctly describes the structure of quartz?

1.   ?    giant covalent structure
2.   ?    giant ionic structure
3.   ?    giant metallic structure
4.   ?    simple molecular structure

Which of the following molecules has the greatest number of lone pairs of electrons?

1.   ?    FLUORINE
2.   ?    HYDROGEN
3.   ?    NITROGEN
4.   ?    OXYGEN

Which of the following substances can conduct electricity?
(1) molten zinc chloride
(2) an aqueous solution of magnesium sulphate
(3) a mixture of ethanol and water

1.   ?    (1) and (2) only
2.   ?    (1) and (3) only
3.   ?    (2) and (3) only
4.   ?    (1), (2) and (3)

Dry zinc chloride solid is a non-conductor of electricity because

1.   ?    it is a non-electrolyte
2.   ?    it exists as molecules
3.   ?    its ions are not mobile
4.   ?    metallic bonding is not present

Element X occurs in nature as two isotopes, 63X and 65X. if the relative atomic mass of X is 63.5, what is the relative abundance of the 63X isotope?

1.   ?    25%
2.   ?    60%
3.   ?    75%
4.   ?    90%

Which of the following statements concerning helium is/ are correct?
(1) the outermost electron shell of a helium atom has an octet structure
(2) helium is used to fill weather balloons
(3) helium exists as monatomic molecules

1.   ?    (1) only
2.   ?    (2) only
3.   ?    (1) and (3) only
4.   ?    (2) and (3) only