Explain the relationship between temperature, energy and motion of particles in an object

Thermal energy is the average kinetic energy (energy related to motion) of a very large set of atoms or molecules. This average kinetic energy depends on the temperature, which is related to the movement of the particles (atoms and molecules) that constitute the substances. That is, the temperature of a substance is a measure of the average kinetic energy of its particles (kinetic energy is the energy of motion).

By increasing the temperature of a material, be it a liquid, solid or gas, what is done is to increase the agitation or movement of each of the particles that compose it. That is, the transferred energy is used by atoms or molecules to increase their kinetic energy.

In short, a body at a low temperature will have less thermal energy than another that is at a higher temperature.

The molecules in a substance have a range of kinetic energies because they don't all move at the same speed. As a subtance absorbs heat the particles move faster so the average kinetic energy and therefore the temperature increases. Kinetic energy is the energy that an object has because of its motion.