How is thermal energy related to particle movement?

Thermal energy is directly related to the movement of particles; the more they move, the higher the thermal energy.

Thermal energy, also known as heat energy, is a type of kinetic energy - the energy of motion. It is associated with the random motion of atoms and molecules in matter. All matter is made up of particles which are constantly moving. The speed at which these particles move is directly related to the amount of energy they have. The faster the particles move, the more energy they have and the higher the temperature of the substance.

When a substance is heated, energy is transferred to its particles, causing them to move faster and collide more frequently. This increase in particle movement results in an increase in thermal energy. Conversely, when a substance is cooled, its particles slow down, collide less frequently, and the thermal energy decreases.

It's important to note that different substances require different amounts of energy to change their temperature. This is known as specific heat capacity. For example, it takes more energy to increase the temperature of water than it does for the same mass of iron. This is because water molecules require more energy to speed up their movement compared to iron atoms.

In gases, the particles move freely and rapidly, resulting in high thermal energy. In liquids, the particles move more slowly than in gases, and in solids, the particles vibrate in fixed positions, resulting in the lowest thermal energy of the three states of matter.

In summary, thermal energy is a measure of the total kinetic energy of the particles in a substance. The more thermal energy a substance has, the faster its particles are moving. This relationship between thermal energy and particle movement is a fundamental concept in understanding how heat is transferred and how different substances react to changes in temperature.