Question

What is the mass of a single water molecule

Answer 1

I am thinking 18 grams.

Answer 2

Water molecule is H2O.
mass of water molecule = 2* mass of H atom + 1* mass of O atom
mass of H atom = 1 amu and that of O atom = 16 amu. hope it helps

Answer 3

when we are dealing with individual atoms and molecules we speak of relative atomic mass and relative molecular mass RAM is the mass relative to the carbon 12 isotope

so relative molecular mass of water is water is 1.008*2 + 16 = 18.016

Answer 4

Atomic mass unit (amu) is relative mass unit, relative wrt carbon-12 isotope.