2)Plants use when they manufacture food. a)carbon dioxide b)nitrogen c)oxygen d)argon

3)Air is a mixture of gases. Which gas is least abundant?
a)hydrogen b)nitrogen c) helium d)oxygen

4)Strong wind can move objects. This force is known as
a) cool air b)gases c)air pressure d)motion

5)Oxygen will cause a glowing fire to
a)go out very quickly b)burn more rapidly
c)get dim d)not to light

6)Which gases are exchanged between human and plants?
a)oxygen and carbon dioxide b)carbon dioxide and nitrogen
c)hydrogen and oxygen d)nitrogen and hydrogen

7)The strong wind blew the flower pot out of its place. This incident shows that air
a)occupies space b) is colourless and odourless
c)exerts pressure d) is made up of different gases.

8)Which gas is needed for plant growth?
a)carbon dioxide b) oxygen c) nitrogen d) neon

9)What is the commonest noble gas in the air?
a) oxygen b) nitrogen c) argon d) neon

10) Which is the only process that produces oxygen?
a) combustion b) respiration c) decay d) photosynthesis

Answer these questions on the lines provided.

1)What is the meaning of the following terms? (3 marks)
a)respiration
b)photosynthesis
c)noble gas?

2)How do you know that air is in an object? (2 marks)


3)List three (3) things which indicate that air is all around us. (3 marks)


4)List three (3) ways in which we use air.(3 marks).


5)What are three (3) main components of air? (3 marks)



this is science its just that theres no science option i am deeply sorry

your question is long but the points are less

Explanation:

2. (carbon dioxide ) a

3. Nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%. (nitrogen )b

4. (air pressure ).c

5. (burn more rapidly)b

6. (oxygen and carbon dioxide)a

7. (exerts pressure )c

8. (carbon dioxide)a

9. (argon)c

10. (photosynthesis)d

1. respiration=the act or process of breathing the inhaling of oxygen and the exhaling of carbon dioxide. the process by which cells use oxygen to break down sugar and obtain energy> It is called respiration.

photosynthesis= Photosynthesis is the process by which plants make their food using carbon dioxide, water, and sunlight.

noble gas= any of a group of rare gases that include helium, neon, argon, krypton, xenon, and usually radon and that exhibit great stability and extremely low reaction rates. called also inert gas.

2. we know air exists because first of all, we breathe it every day and it's necessary for most things living on this earth. You can prove air exists by blowing up a balloon. By doing this, it proves that air has weight and air takes up space. Lastly, the air is just made up of mainly nitrogen and oxygen so air is an object

3. Air is present all around us. We cannot see the air around us but we can feel its presence when the leaves rustle or branches sway. birds fly in the air it's an indicator of air. we breathe in and out we are also an indicator of air.

4. =blowing the balloon

=breathe in and out

=photosynthesis

= energy supplies

=maintaining temperature

5. Nitrogen (78%), Oxygen (21%), Argon (1%), Carbon-di-oxide (0.03%), and water vapor. Air also has some other gases but they are in very minute percentage.

well if u read the book you would know that she meant to