# What is the mass of ONE water molecule?

You know that one mole of water, i.e. ${N}_{A}$ water molecules, has a mass of $18.01 \cdot g$. And thus to get the mass of ONE water molelcule, we divide this molar mass by ${N}_{A} = 6.022 \times {10}^{23}$
And so $\text{mass of one water molecule} = \frac{18.01 \cdot g \cdot m o {l}^{-} 1}{6.022 \times {10}^{23} \cdot m o {l}^{-} 1}$ $=$ ??g