1. Lemon juice is _______ in nature.   neutral   metallic   acidic   basic   Hint Half-n-half Clue   2. Solubility of a substance in a solvent usually increases with an increase in temperature.   True   False   3. The lead of a pencil mainly contains _______.   carbon black   plastics   graphite   lead   Half-n-half Clue   4. Which of the following gases is green in color?   Chlorine   Krypton   Neon   Hydrogen   Half-n-half Clue   5. Fill in the missing word: Acid + _______ = Salt + Water   Base   Non Metal   Metal   Oxygen   Half-n-half Clue   6. A substance that speeds up the rate of a chemical reaction without undergoing any change itself is known as a _______.   catalyst   cation   nucleus   counter ion   Half-n-half Clue   7. Acids turn blue litmus paper _______.   colorless   yellow   pink   red   Half-n-half Clue