Similar term(s): Gamma rays, Radio waves, Visible light, Blue light, Infrared radiation, Ultraviolet radiation.
The electromagnetic spectrum is the entire range of wavelengths of all known
electromagnetic radiations. It includes:
Gamma rays have the smallest wavelengths and highest
frequencies known. They are high energy waves capable of travelling long
distances through air and are the most penetrating waves.
X-rays have longer wavelengths than gamma rays but smaller
wavelengths and therefore higher energy than ultraviolet radiation. They have
been used in various applications in science and industry and are primarily used
in medicine for instance in radiography. They are a form of ionizing radiation
and as such can be dangerous. X-rays are emitted by electrons outside the
nucleus, while gamma rays are emitted by the nucleus.
Ultraviolet (UV) radiation is defined as the portion of the
electromagnetic spectrum between X-rays and visible light.
Visible light – also known as the visible spectrum – is the
portion of the electromagnetic spectrum that human eyes can detect. It covers
all colours from blue at 400 nm to red at 700 nm, with blue light having more
energy than red light.
Infrared (IR) radiation – also referred to as thermal
radiation – is the portion of the electromagnetic spectrum lying between visible
light and microwaves. The most important natural source of infrared radiation is
Radio waves have long wavelengths, ranging from a few
centimetres to many thousands of kilometres in length. They are used among other
things for television, cell phone and radio communications.