Air

_________ is the percentage of nitrogen in air
1. 78
2. 21
3. 0.03
4. 1
Gas exchange takes place in plants using _____________
1. stomata
2. chlorophyll
3. leaves
4. flowers
The constituent of air that supports combustion is_____________
1. nitrogen
2. carbondioxide
3. oxygen
4. water vapour
The gas given out during photosynthesis
1. argon
2. oxygen
3. carbondioxide
4. nitrogen
___________can be seen moving in a beam of sunlight in a dark room
1. oxygen
2. carbon dioxide
3. dust particles
4. nitrogen
movement of air takes place in ___________ layer
1. troposphere
2. stratosphere
3. ozone
4. ionosphere
______________ is responsible for making clouds
1. hydrogen
2. oxygen
3. water vapour
4. carbondioxide
____________ layer contains the ozone layer
1. troposphere
2. stratosphere
3. mesosphere
4. exosphere
___________ respire using their skin
1. fish
2. frog
3. rats
4. humans
____________discovered nitrogen
1. lavoisier
2. rutherford
3. ingenhousz
4. joseph priestley