# When a substance is compressed what happens to its density?

Feb 22, 2018

The density increases.

#### Explanation:

We know that density, $\rho$, is denoted by $\rho = \frac{m}{V}$.

Since, according to Boyle's Law, $P \propto \frac{1}{V}$, as pressure increases, volume decreases.

We also know that $\rho \propto \frac{1}{V}$, or $V \propto \frac{1}{\rho}$.

By the above, we can say that when volume decreases, density increases.

Therefore, when a gas is compressed its density increases.