(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

State what are synthetic detergents. Explain experimentally how you will determine the advantage of synthetic detergents over soap using a sample of hard water.

Select the correct answer from the choice given in the options.

A substance which causes hardness in water _____.

Name or state the following:

A substance added to remove both temporary and permanent hardness in water.

Select the correct answer from the answer in the bracket to complete the sentence.

An element has electronic configuration 2, 8, 1 and 12 neutrons. Its mass no. is ________.

Select the correct answer from the answer in the bracket to complete the sentence.

An element has electronic configuration 2, 8, 1 and 12 neutrons. Its mass no. is ________.

Select the correct answer from the answer in the bracket to complete the sentence.

An atom with electronic configuration 2, 7 and mass number 19 will have ________ neutrons.

Select the correct answer from the answer in the bracket to complete the sentence.

An atom with electronic configuration 2, 7 and mass number 19 will have ________ neutrons.

Give a reason for the following:

The mass number of an atom is slightly less than the actual atomic mass.

Give a reason for the following:

The mass number of an atom is slightly less than the actual atomic mass.

State the characteristics which remain similar in moving down in a group of the periodic table.

Write a short note on the following type of element –

alkali metals

Write a short note on the following type of element –

alkaline earth metals

Write a short note on the following type of element –

halogens

Write a short note on the following type of element –

noble gases

‘The periodic table contains elements methodically grouped together’.

State the main helpful features of the long form of the periodic table.

Name or state following with reference to the element of the first three periods of the periodic table.

An alkaline earth metal in period 3.

Select the correct answer from the options given below.

The most reactive halogen from group 17.

Give a reason for the following:

Noble gases do not form compounds readily.

Give a reason for the following:

Group 1 [I – A] elements are called alkali metals.