Which of the following best explains why the pressure exerted by carbon dioxide on the walls of a sealed container increases when dry ice (solid CO2) sublimates?

This statement is incorrect because gas particles actually exert more force on the container walls due to their rapid movement and increased number. When CO2 transitions from solid to gas, the pressure increases, showing that gas particles exert greater force as they collide more frequently with the walls.

This statement is misleading since gas CO2 molecules move faster in the gaseous state compared to their solid state. In the solid form, CO2 molecules are held in a fixed position and do not move freely, thus they cannot exert pressure until they sublimate into gas and gain kinetic energy.

This choice is incorrect as it misrepresents the behavior of CO2 molecules. During sublimation, CO2 does not combine to form larger molecules; instead, individual CO2 molecules remain unchanged but increase in number, leading to increased pressure through more frequent collisions.