Electromagnetic radiation that is perceived by the human eye and ranges from red to violet.
gamma rays
Electromagnetic waves of very high frequency that are emitted by radioactive bodies; they are the most radiant and harmful rays and are used especially in treating cancer.
X-rays
Electromagnetic waves used especially in radiology; frequent exposure can be harmful.
ultraviolet radiation
Electromagnetic waves used especially to tan skin and in microscopy, medicine and lighting (fluorescent tubes).
infrared radiation
Electromagnetic waves emitted by warm objects; their many uses include heating, medicine, aerial photography and weaponry.
microwaves
Very short electromagnetic waves; their many applications include radar detection and microwave ovens.
radio waves
Very long electromagnetic waves (about 1 meter) having low frequency; they are used to transmit information (television, radio).
