1. The two allotropes of phosphorus are _______ and _______.   Alpha, Beta   Crystalline, Amorphous   Rhombic, Monoclinic   Red, Yellow   Hint Half-n-half Clue   2. Heat is liberated in _______ reactions.   endothermic   substitution   exothermic   all chemical   Half-n-half Clue   3. A substance that speeds up the rate of a chemical reaction without undergoing any change itself is known as a _______.   catalyst   counter ion   nucleus   cation   Half-n-half Clue   4. What gas is evolved when dilute sulfuric acid is added to zinc?   Argon   Hydrogen Peroxide   Hydrogen   Sulfur Dioxide   Half-n-half Clue   5. Fill in the missing word: Acid + _______ = Salt + Water   Non Metal   Oxygen   Metal   Base   Half-n-half Clue   6. Catalysts speed up the rate of chemical reactions.   True   False   7. The 'fizz' in soft drinks is caused by _______.   nitrogen   hydrogen   helium   Carbon dioxide   Half-n-half Clue