ICSE ICSE Class 7 - CISCE Question Bank Solutions for Chemistry

A fuel when used releases least amount of pollutants in the air.

Name the main components of air.

State three uses of water vapour in the air.

Describe a simple experiment to show that l/5th of air is oxygen.

Fill in the blank space by choosing the correct word from the given list.
List: oxygen, carbonic, suIphurUioxide gas, precipitation, helium

Dust particles help in the ________ of water vapour in air.

Fill in the blank space by choosing the correct word from the given list.
List: oxygen, carbonic, suIphurUioxide gas, precipitation, helium

_______ gas is used for filling weather observation balloons.

Fill in the blank space by choosing the correct word from the given list.
List: oxygen, carbonic, suIphurUioxide gas, precipitation, helium

Solution of carbon dioxide in water is called _________ acid.

Statement given below is incorrect. Write the correct statement :

Carbon dioxide gas allows the earth to radiate out heat rapidly.

Statement given below is incorrect. Write the correct statement :

Helium gas at low pressure is used for filling electric bulbs.

Statement given below is incorrect. Write the correct statement :

Symbiotic bacteria are present in nodules of cereal plants such as wheat.

Statement given below is incorrect. Write the correct statement :

During thunder and lightning, nitrogen and oxygen combine to form nitrogen dioxide gas.

Write ‘True’ or ‘False’ in front of following statement.

Water containing dissolved carbon dioxide can dissolve marble.

Write ‘True’ or ‘False’ in front of following statement.

The area where a lot of fuel burns has more percentage of carbon dioxide.

Write ‘True’ or ‘False’ in front of following statement.

The trapping of solar heat energy in the earth’s atmosphere is called greenhouse effect.

Tick (√) the most appropriate answer.

A gas which dilutes the activity of oxygen in air is:

Tick (√) the most appropriate answer.

Symbiotic bacteria is not present in the nodules of :

Tick (√) the most appropriate answer.

The presence of water vapour in air is essential for :

Tick (√) the most appropriate answer.

Which is not a polluting gas for the air?

Tick (√) the most appropriate answer.

The humans pollute the air by :

Briefly state the importance of Oxygen.