Question

What happens when gas is cooled?

Answer 1

A "change in state" occurs when a substance changes its state, such as when ice melts to produce liquid water. When energy is supplied or removed from a substance, it affects the way the particles interact with one another, causing changes in state. When a substance is heated, cooled, or exposed to a change in external pressure, it can change its state.

Complete answer:
When a gas is cooled, the particles stop moving around as quickly and form a liquid. As a result, there is a phase shift. Condensation is a process that occurs at the same temperature as boiling. As a result, a substance's boiling point and condensation point are the same temperature. The boiling and condensation points of a substance are the temperatures at which the substance becomes gas and liquid, respectively.
When a gas is cooled, a variety of things can happen. The following are a few of them:
There is a thermal energy loss.
Gas particles lose kinetic energy and move slower as a result.
The amount of interparticle space between gas particles shrinks.

Note:
When a substance is heated, it releases energy, which causes the particles to become more active, vibrating, rotating, and even moving faster. If a substance has enough energy, it can overcome the bonding forces that hold the particles together and undergo a state shift. Cooling eliminates energy from the particles, making them less active and allowing the bonding forces inside the substance to take hold.