What happens to the number of molecules inside a balloon as it is submerged underwater?

When a balloon is submerged underwater, the number of gas molecules inside the balloon remains the same. This is because the balloon is a closed system, and the gas contained within is not being added to or lost; it is simply experiencing changes in pressure and volume due to the surrounding water pressure.

As the balloon descends into the water, the external pressure increases, which can compress the gas inside, reducing the volume of the balloon. However, the actual count of gas molecules within the balloon does not change; all the molecules that were inside before submersion are still present afterward.

Therefore, while the physical dimensions of the balloon may alter due to the effects of pressure, the quantity of gas molecules remains constant. Understanding this principle is fundamental in grasping the behavior of gases under different pressure conditions in a dive environment.