Answer 1

The significance of the formula H₂O is:

It represents one molecule of water.

It provides important information on the constituents of water i.e. hydrogen and oxygen, through the chemical formula.

It also provides information on the number of atoms of each element present in one molecule of water.

It refers to the presence of one mole of molecules of water; it refers to 6.022 × 10²³ molecules of water.