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

Write the name of the following compound:

K₂PbO₂ 

Write the name of the following compound:

Cr₂(SO₄)₃ 

Write the name of the following compound:

Na₂O

Fill in the blank with the correct word from the options given below:

Compounds are always _______ in nature.

In the figure given alongside

(a) Name the shells denoted by A,B, and C. Which shell has least energy

(b) Name X and state the charge on it

(c) The above sketch is of …………. Model of an atom

Give the postulates of Bohr's atomic model

Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common.

State the chemicals responsible for ozone layer destruction.

What is an ozone layer. State the distribution of the ozone layer in the stratosphere.

Give balanced equations for formation of ozone molecules from oxygen molecules. What type of reaction takes place, during the formation.

How is the ‘ozone oxygen cycle’ maintained in the stratosphere and state what disturbs the balance, resulting in ozone depletion or destruction, Give balanced equation for the same.

Enumerate the damage to humans, animals and plants caused due to ozone depletion.

Name the chemicals responsible for destruction of the ozone layer. State the main chemical from these chemicals, which is responsible for more than 80% ozone depletion.

State the role of chlorofluorocarbons in ozone destruction or depletion [no equations required].

Enumerate methods of protecting the ozone layer and preventing its depletion.

State how CFCs break ozone in the stratosphere.

Select the correct answer from the following statement:

The gas which in presence of U.V. light gives two atoms of the same gas.

Select the correct answer from the following statement:

A chemical responsible for ozone depletion.