1. Acids change a litmus paper from   Blue to Red   Green to White   Red to Blue   Red to Purple   Hint Half-n-half Clue   2. Which of the following is not an acid?   HCl   H2SO4   HNO3   NaOH   Half-n-half Clue   3. The lead of a pencil mainly contains   Plastics   Lead   Carbon Black   Graphite   Half-n-half Clue   4. What is the combination of any substance with oxygen known as?   Oxidation   Combustion   Hydrogenation   Reduction   Half-n-half Clue   5. A substance that absorbs moisture is known as   Hygroscopic   Hydrophobic   Amorphous   Hydrophilic   Half-n-half Clue   6. Which of the following gases is green in color?   Krypton   Chlorine   Neon   Hydrogen   Half-n-half Clue   7. Which of the following is not a physical change?   Decantation   Precipitation   Oxidation   Distillation   Half-n-half Clue