The average kinetic energy of the particles in a substance is a statistical measure that reflects the overall energy of the entire system of particles, rather than the energy of each individual particle. In a substance made up of 1,000 particles, the average kinetic energy is calculated by taking the total kinetic energy of all the particles and dividing it by the number of particles (in this case, 1,000).
This means that while individual particles may have varying kinetic energies (some moving faster and some slower), the temperature provides a single value that represents the mean or average kinetic energy of all the particles in that substance. Therefore, the average kinetic energy is a way to quantify the overall motion and thermal energy of the system, which is directly related to the temperature of the substance.
In summary, temperature measures the average kinetic energy of the particles in a substance, capturing the collective behavior of many individual particles' motions.