# Question 6dadc

Sep 10, 2017

The average atomic mass of the given sample of bromine is $80$.

#### Explanation:

Since they both make up an abundance of 50%, just add $79$ and $81$, then divide by $2$.

$79 + 81 = 160$

$\frac{160}{2} = 80$

The following is probably what your teacher wants you to do. Multiply the given mass numbers by the decimal form for 50%#, 0.50, and add them together.

$\left(0.50 \times 79\right) + \left(0.50 \times 81\right) =$

$39.5 + 40.5 = 80$