9702 · 14.2
Temperature scales — FAQ
Frequently asked questions for 9702 Temperature scales. Direct answers first, then deeper explanation — then practise with marking.
Why is Kelvin called an 'absolute' temperature scale?
It's called absolute because its zero point (0 K) represents the lowest possible energy state for matter, meaning there are no negative temperatures, and its readings are independent of any specific substance's properties.
Can I get negative temperatures on the Kelvin scale?
No, the Kelvin scale starts at absolute zero (0 K), which is the theoretical minimum temperature. Therefore, there are no negative temperatures on the Kelvin scale.
What physical properties are used in thermometers?
Common properties include the change in electrical resistance of a material, the expansion of a liquid (like mercury or alcohol), the pressure change of a gas, or the voltage generated in a thermocouple.