ICSE ICSE Class 7 - CISCE Question Bank Solutions

State a specific reason for using gold in jewellery

State whether the statement given below is true or false. If false write the correct statement.

Silicon is an example of a metalloid.

Differentiate between the following with suitable examples- A basic radical and an acid radical

Fill in the blank:

A radical with one atom of sulphur and three atoms of oxygen are __________.

Select the correct answer to the statement given below:

An elementary particle of matter – of a group of atoms of different elements behaving as a single unit with charge on the group.

Match the radicals in List I with their correct names from List II.

Name the following:

The radical containing one nitrogen and four hydrogen atoms.

Answer the question put against the following constituents of air:

Nitrogen : Explain its significance for plants and animals.

Answer the question put against the following constituents of air :

Oxygen : What is the percentage proportion of oxygen in air ? Why is oxygen called active air.

Answer the question put against the following constituents of air :

Water vapours : Explain their role in modifying the earth’s climate.

Define the term Global warming.

Define the term smog.

“Air is a mixture”. Support this statement citing at least three evidences.

What is air pollution ? What are the harmful effects of sulphur dioxide, nitrogen dioxide and hydrogen sulphide present in the air ?

Answer the question put against the following constituents of air :

Carbon dioxide : “Although carbon dioxide plays no role in respiration, all life would come to an end if there is no carbon dioxide in air.” Support this statement with relevant facts.

What are the causes of air pollution?

Suggest five measures to prevent air pollution.

What is nitrogen-fixation?

What are the two ways in which nitrogen fixation occurs?

Explain the conversion of nitrogen into nitrates during lightning.