Name the element having the following symbol:

$\mathrm{Pb}$

Write down the molecular formula for each of the given molecule:

Oxygen

Write down the molecular formula for the given molecule:

Chlorine

Write down the molecular formula for the given molecule:

Nitrogen

Write down the molecular formula for the given molecule:

Hydrogen

Write down the formula for the following compound:

Zinc chloride

Write down the formula for the following compound:

Carbon dioxide

Write down the formula for the following compound:

Potassium hydroxide

Write down the formula for the following compound:

Zinc sulphide