Cognito facts

Key Features: Kelvin

• Zero kelvin (0 K) represents the lowest conceivable temperature, known as absolute zero.

• At 0 K, particles possess the least possible internal energy and all motion theoretically stops.

• As temperature increases above 0 K, particles acquire more internal energy, which is linked to their motion.

Understanding absolute zero

The kelvin scale, also known as the absolute or thermodynamic temperature scale, is fundamental in thermal physics.

Unlike the Celsius scale, which is based on the freezing and boiling points of water, the Kelvin scale is independent of the properties of any specific substance.

Understanding the relationship between temperature and internal energy

Temperature is directly linked to the internal energy of particles in a substance. Higher temperatures correspond to greater internal energy, indicating increased particle movement.

Conversely, lower temperatures signify reduced internal energy and decreased particle activity.

Key points of the relationship between temp and internal energy

• Internal energy is the sum of the kinetic and potential energy of particles in a system.

• Increasing the temperature of a substance increases the mean kinetic energy of the particles in the substance

• When a substance changes state, the position of the particles changes and hence the potential energy changes.

• There is no change in kinetic energy during a change of state.