Give two examples of triatomic molecule.

Write the names of the elements present in the following compound.

Ammonia

State whether the following statements are true or false. If false rewrite the correct form of statements.

A mixture is a pure substance.

State whether the following statements are true or false. If false rewrite the correct form of statements.

The symbol of nitrogen is $\mathrm{N}$

State whether the following statements are true or false. If false rewrite the correct form of statements.

${\mathrm{H}}_2$ represents two molecules of hydrogen.

Find out the odd one out. Give reasons for your choice.

Aluminium, copper, nitrogen and gold

Find out the odd one out. Give reasons for your choice.

Hydrogen, nitrogen, bromine and chlorine