Question

How does the kinetic molecular theory explain the fact that gases condense into liquids?

Answer 1

Condensation of gases into liquids by kinetic molecular theory:

The "kinetic molecular theory" explains the states of matter based on the matter composed of very tiny little particles that are constantly in motion. The theory also explains the observable properties and behaviors of solids, liquids, and gases.

Condensation of particles of a real gas to form liquid is due to the attractive forces present in between them. During the condensation process, gas molecules slows down and come together to form a liquid.  And also during the transfer of energy to something cooler, the process slows down and they attract the bond to become liquid.  Each particle motion is completely independent. The kinetic energy of gas particles is dependent on the temperature of the gas.