The term for the measure of the average kinetic energy of the particles in a substance is temperature. Temperature reflects how fast the particles are moving; higher temperatures indicate greater kinetic energy, leading to increased molecular motion. This measurement is essential in various scientific fields, including thermodynamics, where understanding temperature is crucial for studying heat transfer and phase changes. Temperature is commonly measured in degrees Celsius, Kelvin, or Fahrenheit, making it a fundamental concept in both physical and chemical processes.