Grade 4 (age 9-10)

grade 4 Heat Transfer

A metal spoon left in hot soup gets hot all the way up to the handle, and switching on a heater warms the room even some distance away. Heat always moves from somewhere hotter to somewhere colder, and how it travels comes in three kinds depending on the material. In conduction, particles in a solid pass heat along to their neighbours; in convection, a liquid or gas moves and carries heat with it; and in radiation, heat crosses straight over even with no material in between. Pick each of the three with the buttons and compare in the pictures what the heat travels through.

How does heat travel?

🔥 How heat moves: Conduction

①In conduction, particles in a solid jiggle in place and pass heat on to their neighbours one after another

②A metal spoon in hot soup getting hot at the handle is conduction

③Metals pass heat on well, while wood and plastic do not

④That is why a frying pan's body is metal and its handle is wood or plastic

Summary

Three ways heat travels

Conduction (solids) / Convection (liquids · gases) / Radiation (even without matter)

Heat always moves from hotter places to colder places

🎯 Key points

①Heat moves from hotter places to colder places

②Conduction: particles in a solid pass heat to their neighbours

③Convection: a liquid or gas carries heat as it circulates

④Radiation: heat crosses even empty space

⑤Insulators such as cotton wool and polystyrene foam slow down the movement of heat

Examples and Unit Test

Example 1

A metal spoon left in hot soup got hot right up to the handle. How did the heat travel?

Conduction is heat moving along a solid from the hot end to the cold end.

The heat in the part dipped in the soup passed along the spoon, bit by bit, up to the handle.

▸ Conduction

A wooden spoon left in the soup stays much cooler at the handle, because wood does not pass heat on well.

Example 2

Water at the bottom of a kettle warming and rising, and the sun's heat reaching Earth: which way does heat travel in each?

A warmed liquid or gas rising while the cooler part sinks is convection.

Heat crosses the space between the sun and Earth even though there is almost no material there, so that is radiation.

▸ Boiling water = convection / the sun's heat = radiation

Convection needs material to move, but radiation happens even without any.

Unit-test style

Which statement about how heat moves is correct?

①Heat moves from colder places to hotter places

②Radiation carries heat even without any material

③Conduction happens mostly in gases

④Convection happens easily in solids

⑤Wood passes heat on better than metal

▸ ② Radiation carries heat even without any material

Radiation carries heat even through nearly empty space, like the sun's heat reaching us.

Heat moves from hotter to colder places (①), conduction happens mostly in solids (③), convection happens in liquids and gases (④), and metal passes heat on better than wood (⑤).

← Previous

Shadows and Mirrors

Weight Measurement

Last updated 2026-10-17