Water · H2O

Water: formula H2O, atom count, element breakdown and calculated molar mass.

CompoundH₂O

H₂O

Molar mass18.015 g/mol

Atoms3

Elements2

Hydrogen

2 × 1.008 · 11.19%

2.0160

Oxygen

1 × 15.999 · 88.81%

15.9990

The formula H₂O contains 3 atoms in total. Numbers after element symbols show how many atoms of each element are present.

Molar mass is the sum of the contributions shown above. The percentages show how much each element contributes to the total mass.