What is the temperature?

Temperature is a fundamental concept in physics that describes the degree of hotness or coldness of a substance. It's directly related to the average kinetic energy of the atoms or molecules within a system. The hotter something is, the faster its particles are moving.

Temperature is typically measured using various temperature scales, the most common of which are Celsius (°C), Fahrenheit (°F), and Kelvin (K). Kelvin is an absolute temperature scale, meaning that 0 K represents absolute zero, the theoretical point at which all atomic motion stops.

Temperature plays a crucial role in many physical processes, including heat transfer, chemical reactions, and the states of matter (solid, liquid, gas, plasma). Changes in temperature can cause materials to expand or contract, and can even lead to changes in their physical state.

The measurement of temperature is performed using thermometers, which rely on various physical phenomena that change with temperature, such as the expansion of a liquid or the change in electrical resistance of a material.