What is absolute zero defined as in terms of gas pressure?

Absolute zero is defined as the theoretical temperature at which a gas's pressure is zero when considering an ideal gas. According to the ideal gas law, which states that pressure is directly proportional to temperature, if you lower the temperature of a gas to absolute zero (0 Kelvin), the molecular motion theoretically comes to a complete halt. As a result, the gas would exert no pressure.

This concept arises from kinetic theory, where temperature is related to the average kinetic energy of molecules. At absolute zero, the energy of the gas particles is minimized, and they cannot move any slower. Consequently, a fixed mass of an ideal gas would have a pressure of 0 at this temperature, reinforcing the definition of absolute zero.

The other options do not align with the meaning of absolute zero in terms of gas pressure. For example, the idea of maximum pressure contradicts the behavior of gases at extremely low temperatures, while a fixed pressure of 1 atm does not relate to absolute zero, which is defined in terms of vanishing pressure. Negative pressure is a concept not observed in classical physics in the context of real gases under normal conditions.