1. Catalysts speed up the rate of chemical reactions.   True   False   2. The 'fizz' in soft drinks is caused by _______.   helium   Carbon dioxide   nitrogen   hydrogen   Hint Half-n-half Clue   3. If no more solute can be dissolved in a solvent at a given temperature then that solution is called _______.   an unstable solution   a real solution   a dispersed solution   a saturated solution   Half-n-half Clue   4. The two allotropes of phosphorus are _______ and _______.   Crystalline, Amorphous   Alpha, Beta   Rhombic, Monoclinic   Red, Yellow   Half-n-half Clue   5. Which of the following is not an allotrope of carbon?   Charcoal   Graphite   Silk   Diamond   Half-n-half Clue   6. A pH below 7 indicates _______.   acidity   alkalinity   presence of ions   purity of the sample   Half-n-half Clue   7. The lead of a pencil mainly contains _______.   lead   graphite   plastics   carbon black   Half-n-half Clue