The warmth of the Sun reaches us across the vacuum of space, where there is nothing to conduct or carry it. That is thermal radiation: infrared waves that need no material at all, soaked up best by dull dark surfaces and reflected by shiny ones.
Thermal radiation is the transfer of energy by infrared electromagnetic waves and needs no medium, so it can travel through a vacuum. Dull black surfaces are the best emitters and absorbers; shiny, light surfaces are poor emitters and absorbers but good reflectors.
Thermal radiation (infrared radiation) is the transfer of energy by electromagnetic waves, and it requires no medium.
Hotter objects radiate more energy. A dull black surface both absorbs and emits best.
Compare surfaces and temperatures and watch how much infrared radiation each one emits.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
Thermal radiation is transferred by...
Unlike conduction and convection, radiation can travel through...
The best emitter of thermal radiation is a...
A shiny, light-coloured surface is a good...
The same surface property controls both how well an object emits radiation and how well it absorbs it.
A good absorber of radiation is also a good emitter. A dull black surface both takes in and gives out infrared well, while a shiny silver surface does both poorly. The same property governs absorbing and emitting.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Energy reaches the Earth from the Sun through space by...
A teapot is given a shiny surface in order to...
Two identical cans of hot water, one dull black and one shiny, are left to cool. The black one cools faster because it is a...
That completes the core heat-transfer trio. Keep the chain going.