Electromagnetic Waves

They transfer energy

Travel at a constant speed of 3 x 10^8 ms-1 in vacuums

They can travel through a vacuum

Obey the laws of Refraction and Reflection

Travel in transverse waves

Do not carry electric charge

Radio Waves

30Hz-300GHz

Emitted by lightning and astronomical objects
Generated by radio transmitters.

Used to transmit information
E.g. radio,radar and RC vehicles

A strong enough beam of radio waves can penetrate the eye and heat the lens enough to cause cataracts.

Mircowaves

300MHz-300GHz

Emitted by warm objects

Used in Communication, GPS and Microwave ovens

Infrared

430THz-300GHz

Emitted by warm objects

All objects emit and absorb infrared radiation, thus becoming hotter.

Commonly used for heat detectors, Infrared rays
are used in Thermal cameras and Intruder Alarms.
Other usages are Remote Controls.

Visible

used for optical fibres in telecommunication, lasers
for medical and industrial uses and photosynthesis

emitted by sun

Ultraviolet

used to detect forgery in bank notes, artificial suntanning
sterilising and disinfecting equipment

emitted by sun

Prolonged exposure to ultraviolet rays increases your risk of developing skin cancer.

Emitted by high energy electrons

Used as a diagnostic tool in medicine and dentistry

Analysing the structure of a crystal

Airport baggage scanner

Checking flaws in metals

Living cells and tissue can be damaged by X-rays. This is because X-rays carries enough energy to remove electrons from atoms or molecules, thereby ionizing them. Over exposure to X-rays increase the risk of developmental problems and cancer. The risk of radiation is greater to a fetus, so pregnant patients are advised to avoid exposure to X-rays.

Gamma Ray

Emitted by radioactive nuclei

To kill cancer cells

Sterilising medical equipments

Able to destroy brain tumours

Gamma Rays are even more harmful to living cells and tissue than X-rays. This is because Gamma Rays carry enough energy to remove electrons from atoms or molecules, thereby ionizing them.