When matter is heated it tends to

get hotter

It gets hotter certainly is correct. Expands may be another possibility if you are looking for another word.

expand or increase in volume. This is a result of the increased kinetic energy of the particles that make up matter.

To understand why matter expands when heated, we can look at the behavior of individual particles and their interactions. Matter is composed of atoms or molecules that are constantly moving and vibrating. When heat is added to a substance, it increases the average kinetic energy of these particles.

As the particles gain more energy, they start to move more vigorously and collide with each other. These collisions increase the overall movement and spacing between the particles. With increased movement, the particles spread out, leading to an expansion of the substance.

This expansion is most noticeable in gases because their particles are already spread out and relatively free to move. When a gas is heated, the particles move more rapidly and increase their average distance from each other, causing the gas to expand and occupy a larger volume.

Solids and liquids also expand when heated, although the expansion is not as easily noticeable as gases. In solids, the particles are closely packed and have less freedom to move. However, they still vibrate and gain energy when heated, causing them to slightly shift and increase the overall size of the solid.

In liquids, the particles are less tightly packed than in solids and have some freedom to move around. When heated, the increased kinetic energy causes the particles to move more, leading to a slight increase in volume.

In summary, when matter is heated, the increased kinetic energy of the particles causes them to move more vigorously and collide with each other. This results in an expansion or increase in volume of the substance.