Heat and Temperature: Concept Map

Concept Map

Organise the vocabulary, quantities and relationships into a connected model.

This extension applies that lens specifically to Heat and Temperature.

Temperature tells you how hot or cold something is. It is measured with a thermometer, in degrees Celsius (°C).

Heat is different. Heat is energy on the move — energy transferred from a hotter object to a cooler one. An object does not "contain heat"; it contains thermal energy, and heat is the name for that energy crossing from one place to another.

The rule never varies: heat flows from hot to cold, and it keeps flowing until both objects reach the same temperature. Scientists call that state thermal equilibrium.

Worked example — a mug of rooibos. You pour tea at 82 °C and stand it on the table in a kitchen at 20 °C. Heat flows out of the tea and into the mug, the table and the air. After half an hour the tea reads 24 °C.

The drop in temperature is

And notice what does not happen: the tea never cools below room temperature. Once the tea and the room are at the same temperature, there is no longer a hot side and a cold side, so the flow stops.

Heat and temperature are not the same measurement. A 2 litre pot of water at 60 °C is cooler than a cup of water at 90 °C — but because there is so much more water in the pot, the pot holds far more thermal energy in total. Temperature answers "how hot?"; thermal energy answers "how much?".