Absolute Zero and Kelvins
In 1848 William Thomson came up with the Kelvin scale for temperature. He measured the pressure caused by gases at known temperatures (in °C) and plotted the results. He found a graph like this one.
By extrapolating his results he found the temperature at which a gas would exert zero pressure. Since pressure is caused by the collisions of the gas particles with the container, zero pressure means the particles are not moving and have a minimum internal energy. At this point the particle stops moving completely and we call this temperature absolute zero, it is not possible to get any colder. This temperature is -273°C.
1 Kelvin is the same size as 1 degree Celsius but the Kelvin scale starts at absolute zero.
°C = K – 273 K = °C + 273
| Section 6 | The Specifics | |
|---|---|---|
| Lesson 8 | ||
| Learning Outcomes | To be able to explain and calculate specific heat capacity | |
| To be able to explain and calculate specific latent heat | ||
| To know the correct units to use and the assumptions we make in energy transfer | M.BENYOHAI |