What must remain constant for Boyle's Law to apply?

Boyle's Law describes the relationship between the pressure and volume of a gas at constant temperature. According to this law, if the temperature of a gas remains constant, then the pressure of the gas is inversely proportional to its volume. This means that if the volume increases, the pressure decreases, and vice versa, as long as the temperature remains unchanged.

For Boyle's Law to hold true, pressure and volume are the critical variables that must be allowed to change while keeping the temperature constant. This foundational relationship highlights the behavior of gases under varying conditions and is critical in various applications across engineering and physics. Understanding this principle is essential for predicting how a gas will respond to changes in pressure or volume without accounting for thermal influences.