Kelvin Scale & Absolute Zero
Physics: Edexcel IGCSE, topic 5.3.1
Kelvin Scale and Absolute Zero
Absolute zero defines the start of the Kelvin temperature scale.
Absolute zero
- As we increase the temperature of an object, we give kinetic energy to its particles, making them move around more.
- The hotter an object gets, the more its particles move around.
- Therefore the colder an object gets, the less its particles move around.
- So there must be a temperature where all the particles completely stop moving - they have zero kinetic energy.
- This temperature is called absolute zero.
Absolute zero
- Absolute zero is at 0K or -273°C.
- It is the lowest possible temperature anything can ever reach.
Kelvin temperature scale (K)
- Absolute zero is set as the start of the Kelvin temperature scale.
- The increments of the Kelvin scale are the same as that of the Celsius scale (an increase of 1K is the same as an increase of 1°C).
Kelvin temperature scale (K)
- To convert Celsius to Kelvin, simply add 273.
- To convert from Kelvin to degrees Celsius, simply subtract 273.
- E.g. 100°C is equivalent to 373K.
Test yourself on Kelvin Scale & Absolute Zero
What is absolute zero on the kelvin temperature scale?