Question

How do you calculate the atomic mass of bromine?

Answer 1

See this [site......](https://en.wikipedia.org/wiki/Isotopes_of_bromine)

Explanation:

There only two abundant isotopes of bromine, `50.7%` `""^79Br`, and `49.3%` `""^81Br`. The weighted average of the masses of these isotopes gives `70.9*"amu"`, which is the atomic mass of bromine quoted on the Periodic Table.