Which physical state of matter is most affected by temperatures nearing absolute zero?

The physical state of matter most affected by temperatures nearing absolute zero is gas. As temperature decreases, the kinetic energy of gas particles significantly reduces. At temperatures approaching absolute zero, gas particles slow down considerably and may exhibit phenomena such as condensation into a liquid state or even Bose-Einstein condensation, where they occupy the same space and quantum state.

In contrast, solids and liquids experience less dramatic changes at these temperatures. Solids will remain in their ordered structure, and while they may become more rigid, they do not transition to a significantly different state as gases do. Plasma, composed of ionized gases, requires very high temperatures to exist, and thus is not affected by decreasing temperatures in the same way gases are. Therefore, gases exhibit the most pronounced changes near absolute zero.