1. What is the name given to the respiratory holes on the surface of a leaf?   Stomata   Chlorophyll   Pits   Tendrils   Hint Half-n-half Clue   2. On burning charcoal which of the following gases is produced?   Carbon Dioxide   Hydrogen   Oxygen   Nitrous Oxide   Half-n-half Clue   3. A hygroscopic substance is one which   Absorbs water   Absorbs air   Releases air   Releases water   Half-n-half Clue   4. The atmosphere exerts pressure on the surface of the earth.   True   False   5. Air is   An Element   An Alloy   A Mixture   A Compound   Half-n-half Clue   6. Carbon dioxide is lighter than air.   True   False   7. When hydrogen peroxide acts on Manganese Dioxide, oxygen is produced.   True   False