Question

What is the atomic mass of gallium?

1) 69.723 amu
2) 72.63 amu
3) 63.546 amu
4) 55.845 amu

Answer 1

The atomic mass of gallium is 69.723 amu.

Step-by-step explanation:

The atomic mass of gallium is 69.723 amu (atomic mass units). The atomic mass of an element is the weighted average of the masses of its isotopes. Gallium has two stable isotopes: gallium-69 (68.9256 amu, abundance of 60.11%) and gallium-71 (70.9247 amu, abundance of 39.89%).