What happens to the volume of gas at high pressures?

At high pressures, the volume of a gas decreases as the gas particles are forced closer together. This behavior is described by Boyle's Law, which states that the volume of a gas is inversely proportional to its pressure, provided the temperature remains constant. As pressure increases, the space between gas particles diminishes, resulting in a reduction of volume.

In a practical sense, when you apply high pressure to a gas—such as in a piston—you're compressing the gas particles closer together. This is particularly evident in situations where gas behavior deviates from ideal conditions, specifically at very high pressures when interactions among particles become significant.

The other scenarios do not accurately describe gas behavior under high pressure. An increase in volume, for example, contradicts the fundamental principles of gas laws under high pressure conditions. Additionally, the notion of the volume remaining constant does not account for the significant effects exerted on the gas by increased pressure. A negative volume is not physically meaningful in the context of gas behavior, as volume cannot be negative. Thus, the correct understanding relates directly to how pressure compresses gas molecules, leading to a decrease in volume.