Kelvin

Definition

Kelvin (K) is the base unit of temperature in the International System of Units (SI). It is primarily used in scientific contexts, particularly in astronomy and physics, to measure thermal energy and temperature.

5 Must Know Facts For Your Next Test

1. Kelvin starts at absolute zero, where all thermal motion ceases.
2. The Sun's core temperature is approximately 15 million Kelvin.
3. 1 Kelvin increment is equivalent to 1 degree Celsius increment but starts from absolute zero.
4. Kelvin is essential for understanding blackbody radiation, which explains how stars emit light.
5. Astronomers use Kelvin to calculate the surface temperatures of stars and other celestial objects.

Review Questions

• What is the significance of absolute zero in the Kelvin scale?
• How does the Kelvin unit relate to Celsius when measuring temperature?
• Why do astronomers prefer using Kelvin over Celsius or Fahrenheit?

Related terms

Absolute Zero: The lowest possible temperature where all molecular motion stops, defined as 0 K.

Blackbody Radiation: The emission of light from an idealized object that absorbs all incident radiation, with its spectrum depending on its temperature.

Nuclear Fusion: The process by which multiple atomic nuclei join together to form a heavier nucleus, releasing energy; this process powers the Sun.