Physics · Grades 7–10
Temperature is not total thermal energy
Separate a temperature reading from energy transfer and system size.
Learn the idea
Temperature
Temperature is a state variable related to thermal particle motion in simple models; it is not itself a quantity of heat.
Heat transfer
Heat is energy transferred because of a temperature difference.
Sample size
Two samples at the same temperature can have different internal energies because mass and material differ.
Equilibrium
Net heat transfer between contacting bodies ceases when they reach thermal equilibrium, under an appropriate isolated model.
Worked examples
Two cups at the same temperature must have which property equal?
Equal temperature does not imply equal mass or internal energy.
Temperature
A sample warms from 18 °C to 31 °C. Find temperature change.
31 − 18 = 13 °C.
13 °C
Check your understanding
Heat transfer is caused by which difference in the basic model?
- Colour alone
- A difference in names
- Temperature difference
Why can a large warm bath contain more internal energy than a tiny hotter drop?
Without external intervention, net heat transfer is ordinarily from where to where?
- Cooler to hotter always
- Neither can exchange energy
- Hotter to cooler
Answers and marking notes
Answers and marking notes
- Temperature difference
Heat refers to energy transfer due to temperature difference.
- Internal energy depends on amount and material as well as temperature.
Credit sample size and avoid equating a hotter reading with a greater total automatically.
- Hotter to cooler
This describes spontaneous net thermal transfer between bodies.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.