A deep-sea research probe contains a sealed chamber filled with nitrogen gas at a fixed volume.
The pressure inside the chamber can be measured in pascals (Pa\text{Pa}Pa). Which of the following shows the pascal expressed in SI base units?
A. kg⋅m⋅s−2\text{kg}\cdot\text{m}\cdot\text{s}^{-2}kg⋅m⋅s−2 B. kg⋅m−1⋅s−1\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-1}kg⋅m−1⋅s−1 C. kg⋅m−1⋅s−2\text{kg}\cdot\text{m}^{-1}\cdot\text{s}^{-2}kg⋅m−1⋅s−2 D. kg⋅m2⋅s−2\text{kg}\cdot\text{m}^{2}\cdot\text{s}^{-2}kg⋅m2⋅s−2
As the probe descends into the deep ocean, the temperature of the nitrogen gas inside the sealed chamber decreases. This causes the internal pressure to drop.
Explain, in terms of the behavior of the gas molecules, why the pressure inside the chamber decreases.