Question

What is the atomic mass of water? How is this determined?

Answer 1

Step 1: Define atomic mass

• Each element has its own atomic mass.
• The unit of atomic mass is u(unified mass)

Step 2: The atomic mass of water

• The formula for water is ${\mathrm{H}}_2\mathrm{O}$.
• The atomic mass of water is $18.01\text{u}$.

Step 3: Calculation of atomic mass of water

The atomic mass of water can be calculated by taking separate atomic masses of each element (H and O):

$$\begin{gathered} =2\times \left(\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{H}\right)+\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{O} \\ =\left(1.0079\times 2+16\right)\mathrm{u} \\ =18.0158\mathrm{u} \\ \approx 18.01\mathrm{u} \end{gathered}$$

Therefore, The atomic mass of water is $18.01\text{u}$.