1. Which of the following is not an allotrope of carbon   Charcoal   Graphite   Diamond   Silk   Hint Half-n-half Clue   2. The lead of a pencil mainly contains   Lead   Plastics   Graphite   Carbon Black   Half-n-half Clue   3. Lemon juice is   Acidic   Basic   Neutral   Metallic   Half-n-half Clue   4. Catalysts often speed up certain chemical reactions.   True   False   5. Solubility of a substance in a solvent usually increases with an increase in temperature.   False   True   6. The two allotropes of phosphorus are   Alpha Phosphorus, Beta Phosphorus   Crystalline Phosphorus, Amorphous Phosphorus   Rhombic Phosphorus, Monoclinic Phosphorus   Red Phosphorus, Yellow Phosphorus   Half-n-half Clue   7. Which of the following gases is green in color?   Neon   Krypton   Hydrogen   Chlorine   Half-n-half Clue