1. The 'fizz' in soft drinks is caused by _______.   hydrogen   nitrogen   helium   Carbon dioxide   Hint Half-n-half Clue   2. Heat is liberated in _______ reactions.   substitution   endothermic   all chemical   exothermic   Half-n-half Clue   3. Which of the following gases is green in color?   Hydrogen   Chlorine   Neon   Krypton   Half-n-half Clue   4. Catalysts speed up the rate of chemical reactions.   True   False   5. What gas is evolved when dilute sulfuric acid is added to zinc?   Argon   Sulfur Dioxide   Hydrogen Peroxide   Hydrogen   Half-n-half Clue   6. The two allotropes of phosphorus are _______ and _______.   Alpha, Beta   Crystalline, Amorphous   Red, Yellow   Rhombic, Monoclinic   Half-n-half Clue   7. What is the combination of any substance with oxygen known as?   Reduction   Hydrogenation   Oxidation   Combustion   Half-n-half Clue