Gaseous helium atoms must be cooled to 4.2 K before He liquefies. For elements, this is the lowest liquefaction temperature. Based upon our understanding of gas behavior, explain what is unique about He causing it to liquefy at such a low temperature.

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.