Write the significance of a molecular formula.

The molecular formula of a compound has quantitative significance. It represents:

1. both the molecule and the molecular mass of the compound.
2. the respective numbers of different atoms present in one molecule of the compound.
3. the ratios of the respective masses of the elements present in the compound.

For example, the formula CO₂ means that:

1. the molecular formula of carbon dioxide is CO₂
2. each molecule contains one carbon atom joined by chemical bonds with two oxygen atoms;
3. the molecular mass of carbon dioxide is 44, given that atomic mass of carbon is 12 and that of oxygen is 16.