$\mathrm{NaCl}$ represents one molecule of sodium chloride.

Write the chemical formula and name the elements present in the following compound.

Sodium chloride.

Write the chemical formula and name the elements present in the following compound;

Potassium hydroxide.

Write the chemical formula and name the elements present in the following compound;

Carbon dioxide.

Write the chemical formula and name the elements present in the following compound;

Calcium oxide.

Write the chemical formula and name the elements present in the following compound;

Sulphur dioxide.

Classify the following molecules as the molecules of element or compound.