The Kelvin (K) is the base unit of temperature in the International System of Units (SI). It is named after the Scottish physicist William Thomson, 1st Baron Kelvin. Unlike the Celsius and Fahrenheit scales, which are based on the properties of specific substances, the Kelvin scale is based on the theoretical behavior of ideal gases.

- The Kelvin scale starts at absolute zero, which is the lowest possible temperature where particles have minimal motion.
- A temperature of 0 Kelvin is equal to -273.15 degrees Celsius.
- One kelvin degree is the same as one Celsius degree, but the zero points of the two scales differ.
- Kelvin is used in scientific and engineering applications, especially those involving gas laws and thermodynamics.
- The Kelvin scale is commonly used in situations where precise and accurate temperature measurements are required, such as in scientific research and industrial processes.

To understand the Kelvin scale, it's essential to grasp the concept of absolute zero and the relationship between Kelvin and Celsius temperatures. Here are some key points to focus on while studying Kelvin:

- Understand the concept of absolute zero and its significance in the Kelvin scale.
- Learn how to convert temperatures between Kelvin and Celsius by using the conversion formula:
**T(K) = T(°C) + 273.15**and**T(°C) = T(K) - 273.15** - Explore the applications of Kelvin in scientific research, engineering, and everyday life.
- Understand the Kelvin scale's role in gas laws and thermodynamics, including its use in the ideal gas law equation:
**PV = nRT**(where P is pressure, V is volume, n is the number of moles of gas, R is the ideal gas constant, and T is temperature in Kelvin).

By mastering these key points and understanding the significance of the Kelvin scale, you'll have a solid foundation in the concept of temperature measurement and its applications in the scientific and engineering fields.

PHYSICAL SCIENCE (NGSS)

Energy

Students who demonstrate understanding can:

Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as either motions of particles or energy stored in fields.