Question

Calculate the average atomic mass of hydrogen using the following data:

Isotope	% Natural abundance	Molar mass
1H	99.985	1
2H	0.015	2

Answer 1

Average Atomic Mass = ${\displaystyle \frac{\{(\text{Nautral abundance of}{ }^1\text{H}\times \text{molar mass})+(\text{Natural abundance of}{ }^2\text{H}\times \text{molar mass of}{ }^2\text{H})\}}{100}}$

= ${\displaystyle \frac{99.985\times 1+0.015\times 2}{100}}$

= ${\displaystyle \frac{99.985+0.030}{100}}$

= ${\displaystyle \frac{100.015}{100}}$

= 1.00015 u