ICSE ICSE Class 7 - CISCE Question Bank Solutions

Air has variable composition and hence there is ______ oxygen at lower altitudes than at higher altitudes.

Fill in the blank:

Rusting is a chemical reaction which involves _____ oxidation.

Draw a neat labelled diagram for the following experiment.

To determine the component of air used up in burning, by using phosphorus and a bell jar.

Draw a neat labelled diagram for the following experiment.

To prove that oxygen is non-combustible, but supports combustion.

Draw a neat labelled diagram for the following experiment.

To study the presence of carbon dioxide in air.

Draw a neat labelled diagram for the following experiment.

To prepare oxygen in the laboratory from hydrogen peroxide and a catalyst.

Draw a neat labelled diagram for the following experiment.

To demonstrate the burning of sulphur in a jar of oxygen.

State four differences between – elements, compounds and mixtures with suitable examples.

Select the correct answer to the statement given below:

The chemical name for dinitrogen oxide [N₂0].

Select the correct answer to the statement given below:

A compound containing carbon, oxygen and calcium.

Select the correct answer to the statement given below:

A metalloid

Select the correct answer to the statement given below:

A non-metal which exists in the liquid state.

Select the correct answer from the choice in the bracket.

The least reactive metal.

Select the correct answer from the choice in the bracket.

The positively charged particle of an atom.

Give a reason for the following statement:

Components in a mixture are present in varying proportions and not in a fixed proportion.

State the meaning of the term – (a) atom, (b) molecule, (c) radical – with a suitable example.

Draw the basic structure of an atom representing its –

1. Subatomic particles
2. Nucleus
3. Orbits or shells.

A radical take part – unsplit in a chemical reaction and retains its identity in reactions.
With reference to the radical –

1. ammonium
2. bisulphate
3. carbonate

state the group of atoms present in each radical.

Select the correct answer to the statement given below:

The basic unit of matter is not capable of independent existence.

Select the correct answer to the statement given below:

The smallest particle of a substance – capable of independent existence and which retains the characteristics of the substance.