Question

Explain how gases gases can be liquefied

Answer 1

#Gases can be liquefied by pressurise it.
Gases can pressurise easily as you know. So, when we pressurise the gases, its molecules get tighted, which is a property of a liquid. Liquid's molecules are closer to each other.

#Gases can be liquefied by condensing it.
If we condense(cold) gases, its molecules slower downs and can not move freely everywhere, this is also a property of liquid that this cannot freely movable. By condensing gases, its molecules get closer due to cold.

Answer 2

(1.)Gases can be liquefied by the process of condensation.

(2.)Applying pressure & reducing temperature can liquefy gases.