Class 4 Air Water and Weather

The burning of fire needs

• oxygen.

• carbon dioxide.

• nitrogen.

• water vapour.

Which of the following is NOT true regarding the properties of air? 

• Air occupies space

• Air exerts pressure.

• Air has no mass.

• Air cannot be seen.

When Suresh blew air into a balloon it expanded. This shows that

• air has no mass.

• air fills space.

• air has no weight.

• air is visible.

Asma took two balloons. She blew air with mouth in one balloon and she filled another balloon with the vapours of boiling water. She released the two balloons and observed that the balloon with the hot vapours rose higher than the other balloon. What did she learn from this experiment?

• Hot air is heavier than the cold air.

• Water vapour give energy to the balloon.

• Air likes hot balloons.

• Hot air is lighter and therefore rises higher.

When we blow air into a balloon it expands. What is the reason?

• Air is invisible.

• Air does not occupy space.

• Air has weight.

• Air exerts pressure.

Which of the following does NOT disturb the balance of gases in the air?

• Cutting down trees and forests.

• Releasing polluting gases into the air.

• Growing trees.

• Releasing smoke from the vehicles.

Which of the following changes weather?

• The sun

• Man

• Wood

• Television

Arrow 1 represents

• land breeze

• sea breeze

• movement of water

• movement of soil.

Arrow 2 represents

• photosynthesis

• the direction of the oxygen released by sea

• the direction of sea breeze

• the movement of water.

Land breeze blows

• during the day time.

• noon at.

•  during the night time.

• during mornings.