Answer:
Volume decreases
Explanation:
According to Boyle's Law, the volume of a gas decreases when the pressure increases, because according to Boyle's Law: the volume of a gas is inversely proportional to the pressure it applies. Bearing this into mind, the volume of a gas would increase if the pressure decreases, because the gas is given some more space to expand. On the other hand, if the pressure increases, the gas would have less space, so it result in a decrease of it's volume.
