1. Lime water turns milky after carbon dioxide is passed through it.   True   False   2. Carbon dioxide is lighter than air.   True   False   3. Which gas in the atmosphere saves us from the UV rays of the sun?   Carbon Monoxide   Ozone   Nitrogen   Oxygen   Hint Half-n-half Clue   4. Dry ice is   Ice with salt added   Any Frozen Liquid   Very Cold Ice   Solid Carbon Dioxide   Half-n-half Clue   5. A hygroscopic substance is one which   Absorbs air   Releases air   Releases water   Absorbs water   Half-n-half Clue   6. What gas is evolved when HCl is poured on marble chips?   Calcium Carbonate   Hydrogen   Hydrogen Peroxide   Carbon Dioxide   Half-n-half Clue   7. When we breathe which of the following gases do we use?   Oxygen   Helium   Hydrogen   Carbon Dioxide   Half-n-half Clue