Secondary School (English Medium) (5 to 8) Class 8 - CBSE Question Bank Solutions for Science

Match the terms of column A correctly with the phrases given in column B.

‘Manufacturing synthetic fibres is actually helping conservation of forests’. Comment.

Fill in the blanks:

Metals react with acids to produce _________ gas.

Mark ‘T’ if the statement is true and ‘F’ if it is false.

Generally, non-metals react with acids. ( )

Mark ‘T’ if the statement is true and ‘F’ if it is false.

Sodium is a very reactive metal. ( )

Mark ‘T’ if the statement is true and ‘F’ if it is false.

Copper displaces zinc from zinc sulphate solution. ( )

Give reasons for the following.

Copper cannot displace zinc from its salt solution.

Give reasons for the following.

Sodium and potassium are stored in kerosene.

What happens when Dilute sulphuric acid is poured on a copper plate?

Write word equations of the reactions involved.

What happens when Iron nails are placed in copper sulphate solution?

Write word equations of the reactions involved.

Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.

(a) How will she find the nature of the gas?

(b) Write down word equations of all the reactions taking place in this process.

In an experiment 4.5 kg of a fuel was completely burnt. The heat produced was measured to be 180,000 kJ. Calculate the calorific value of the fuel.

Can the process of rusting be called combustion? Discuss.

Protected forests are also not completely safe for wild animals. Why?

Some tribals depend on the jungle. How?

What are sex hormones? Why are they named so?

Write notes on secondary sexual characters.

Fill in the blanks:

Shooting stars are actually not _________.

Mark the following statement as true (T) or false (F).

Pole star is a member of the solar system. ( )

Explain how you can locate the Pole Star with the help of Ursa Major.