One topic covered in GCSE Science is the transfer of heat (thermal) energy. This is one of eight quizzes on that subject and it looks specifically at infrared radiation.
Infrared radiation is a part of the electromagnetic spectrum. This is a spectrum of waves that also includes light. Infrared is also called thermal radiation and is one way in which heat is transferred. Infrared is emitted (given off), absorbed (taken in) and reflected by all objects. Hotter objects give out more infrared radiation than cooler ones. It has a wavelength of just a little longer than red light waves - you may have seen or done an experiment yourself using a thermometer, prism and light source. When the visible light is dispersed (split into the colours of the rainbow) by the prism, if you hold the thermometer just beyond where the red is, the reading will increase slightly.