1. Carbon dioxide is lighter than air.   True   False   2. What is the name given to the respiratory holes on the surface of a leaf?   Tendrils   Chlorophyll   Stomata   Pits   Hint Half-n-half Clue   3. A barometer is used for measuring   Humidity   Atmospheric Pressure   Annual Rainfall   Temperature   Half-n-half Clue   4. Lime water turns milky after carbon dioxide is passed through it.   True   False   5. When we breathe which of the following gases do we use?   Helium   Oxygen   Carbon Dioxide   Hydrogen   Half-n-half Clue   6. On burning charcoal which of the following gases is produced?   Nitrous Oxide   Carbon Dioxide   Oxygen   Hydrogen   Half-n-half Clue   7. Which gas in the atmosphere saves us from the UV rays of the sun?   Carbon Monoxide   Ozone   Nitrogen   Oxygen   Half-n-half Clue