Hello

The molecular forrmula is H20. One molecule of water consist  of 1 oxygen atom covalently bond with 2 Hydrogen atom.

2 Hydrogen atom +1 oxygen atom = water.

But drinking waters contains chlorine, sodium, aluminium ,magnesium, calcium and traces amount of other ions and molecule.

Good Luck.

H20 is the formula of water. The only substance which has no definite shape is water. The water molecule is composed of 2 hydrogen atoms and 1 oxygen. Each one will be linked by a single chemical bond to an oxygen atom. A single oxygen atom contains 6 electron in its outer shell.