ICSE ICSE Class 8 - CISCE Question Bank Solutions for Chemistry

ANSWER IN DETAIL

Write a note on valence shell.

Indicate which of the following statement is true and which is false: 

The reaction between hydrogen and nitrogen to form ammonia is reversible.

Give reasons for the following:

 Hydrogen can be used as a fuel.

Classify the following changes as physical or chemical:- melting of a solid (wax)

Classify the following changes as physical or chemical:- photosynthesis in plants

Classify the following changes as physical or chemical:-boiling

Write two physical properties of hydrogen.

What is hydrogenation?

Discuss the occurrence of hydrogen in the universe and on the earth ?

Describe two chemical properties of hydrogen with equations.

Discuss the use of hydrogen as a fuel ?

Fill in the blank:

carbon dioxide is used as a..................... in the extraction of pure metals from their corresponding ores.

Define physical change. Give two examples for the above changes.

A burning candle shows both physical and chemical changes. Explain ?

Classify the following as a physical or a chemical change.

Drying of wet clothes

Classify the following as a physical or a chemical change.

Manufacture of salt from sea water

Classify the following as a physical or a chemical change.

Butter getting rancid

Classify the following as a physical or a chemical change.

Boiling of water

Classify the following as a physical or a chemical change.

Burning of paper

Classify the following as a physical or a chemical change.

Melting of wax