Each type of electromagnetic wave has uses that suit its properties. Radio waves are used for television and radio. Microwaves are used for satellite communications and for cooking food. Infrared radiation is used in electrical heaters, for cooking food and in infrared cameras. Visible light is used in fibre optic communications. Ultraviolet waves are used in energy efficient lamps and for sun tanning. X-rays and gamma rays are used for medical imaging and treatments.
(Higher tier) Each use depends on how the waves behave. Radio waves can travel long distances and carry signals to aerials. Microwaves pass through the atmosphere to satellites, but water in food absorbs them, which heats the food. Infrared radiation is absorbed by surfaces, which then heat up, and warm objects emit it, so a camera can detect it. Light stays inside a glass fibre by being reflected along it. In an energy efficient lamp, ultraviolet waves are absorbed by a coating that gives out visible light. Ultraviolet waves also make skin darker, which is a tan. X-rays pass through soft tissue but are absorbed by bone, so they are used for medical imaging. Gamma rays can be directed at a tumour to kill cancer cells, which is a treatment.