Answer:
The pressure of the air molecules inside the pen cap increases and the volume occupied by the air decreases such that the combined volume occupied by the pen cap and the air volume reduces while the combined mass of the pen cap and the air molecules remain the same
Given that density = The mass/Volume, we have that the density varies inversely as the volume, and as the volume reduces, the density increases
Upon squeezing, therefore, as the new combined density of the pen cap and the air molecules rises to more than the density of the water in the bottle, then, the pen cap air molecule is relatively more denser than the water, which will result in the pen cap sinking to the bottom of the bottle
Step-by-step explanation: