1. Which of the following does not belong to this group?   Iron   Sodium   Lead   Oxygen   Hint Half-n-half Clue   2. Iron is magnetic in nature.   True   False   3. Sodium is very reactive and may burn on exposure to air. Therefore, it is kept under _______.   oil   water   ice   acids   Half-n-half Clue   4. Brass is _______.   an element   an alloy   a compound   a mixture   Half-n-half Clue   5. Metals are usually good conductors of heat and electricity.   True   False   6. Rust on iron is basically _______.   a chloride   a nitride   a sulphide   an oxide   Half-n-half Clue   7. Fill in the missing word: _______ + oxygen = Magnesium oxide   carbon   manganese   magnesium   metal   Half-n-half Clue