What scientific principle explains the behavior of air density with altitude changes?

The correct answer is Boyle's Law, which states that at a constant temperature, the pressure of a gas is inversely proportional to its volume. As altitude increases, air pressure decreases, leading to a corresponding increase in the volume of air, which in turn causes a decrease in air density.

At higher altitudes, the weight of the air above pushes down with less force, resulting in lower atmospheric pressure. As a result, the same amount of air occupies a larger volume, causing the density to decline. This principle is crucial for understanding how air density affects various phenomena, such as the performance of aircraft and the behavior of gases in the atmosphere.

Although the other choices are significant in their own contexts—like Bernoulli's Principle, which deals with fluid dynamics, and Archimedes' Principle, which is focused on buoyancy—Boyle’s Law specifically describes how pressure and volume changes impact gas density with altitude variations.