# Question #07b70

May 18, 2017

See below.

#### Explanation:

Mass of substance $\text{= 184.1 g}$
It contains 2 Br

$\therefore$ mass of $\text{Br" = 79.9 xx 2 = "159.8 g}$

It contains one other atom, X

$\therefore$ mass of $\text{X" = 184.1-"159.8 g" = "24.3 g}$

In the periodic table, the element with a mass of $\text{24.3 g}$ is Mg. Thus X is Mg.

Hope this helps :)