What does Dalton's Law state about the behavior of gases?

Dalton's Law pertains to the behavior of gases in a mixture and essentially states that in a mixed gas system, the total pressure exerted by the mixture is equal to the sum of the partial pressures of each individual gas present. This principle is foundational in understanding how different gases interact in a closed environment, especially in scenarios involving varying pressures.

The correct choice reflects the idea that while the total pressure of a gas mixture can change, the individual partial pressures of the gases remain constant if the composition of the gas mixture does not change. This is essential when calculating how gases will react or behave under different pressure conditions in various scenarios such as in trauma settings where oxygen and carbon dioxide levels can significantly impact patient outcomes.

The other options do not align with the principle described by Dalton's Law. For example, temperature being constant, gas volume being solely affected by temperature, and gas density being inversely related to pressure are concepts rooted in other gas laws, such as Boyle's Law or Charles's Law, rather than Dalton's Law. Understanding the unique role of Dalton's Law in the behavior of gases helps in applying these concepts in practical situations, particularly in critical care scenarios.