Basics about Temperature
You don’t need a science book to tell you that the word hot means higher temperatures or the word cold means lower temperatures. When scientists think about high and low temperatures, however, they do not think about “hot” and “cold.” Instead, they think about particles of matter in motion.
Recall that all matter is made up of tiny particles. These particles are always moving even if the matter they make up is stationary. Recall that the energy of motion is called kinetic energy. So all particles of matter have kinetic energy. The faster particles move, the more kinetic energy they have. Temperature is a measure of the average kinetic energy of the individual particles in matter.
In this picture, the hot cocoa has a higher temperature than the cold chocolate milk. The cocoa’s particles are moving faster, so they have greater average kinetic energy. If the milk is heated, its particles will move faster, so their kinetic energy will increase. The temperature of the milk will rise
