Electromagnetic waves and black body radiation GapFill

Electromagnetic waves are transverse waves in electric and magnetic fields. Electromagnetic waves can have a variety of wavelengths and frequencies, forming a continuous spectrum.
The regions of the electromagnetic spectrum with some applications, from longest to shortest wavelength, are:

• radio waves - television and radio broadcasts
•  ultravioletvisible lightradio wavesmicrowavesinfraredgamma rays - satellite communications, cooking food
•  gamma raysinfraredultravioletradio wavesmicrowavesvisible light - electrical heaters, cooking food, thermal cameras
• visible light -  medical imaging and treatmentsheatingcooking foodWi-Fifibre-optic communicationssatellite communications
•  microwavesgamma raysinfraredvisible lightultravioletradio waves - hospital sterilisation, suntanning
• X-rays and gamma rays -  fibre-optic communicationsWi-Ficooking foodheatingsatellite communicationsmedical imaging and treatments

Gamma waves are produced by  hot objectselectrons moving between orbitalsoscillations in electrical currentsrotating atomschanges in nucleichanging magnetic fields.

When light moves from one material into another, it can change direction due to the change in speed of the light; this is called  refractiontransmissionpolarisationreflectionabsorptiondiffraction and is used in lenses.
Lenses can change the apparent size of an object; the change in size is known as magnification, which is given by the equation magnification =  object size - image sizeimage size × object sizeimage size - object sizeobject size ÷ image sizeimage size ÷ object sizeimage size + object size.
Lenses can either be either (the outer edge is thicker than the middle) or convex (the middle is thicker than the edge). Concave lenses produce images which  are always larger than the objectare always realare always virtualare always smaller than the objectcan be either virtual or realare always the same size as the object, and convex lenses produce images which  are always smaller than the objectcan be either virtual or realare always virtualare always the same size as the objectare always larger than the objectare always real.

Visible light can have many different colours, called the colour spectrum, which includes red, orange, yellow, green, blue, indigo and violet. Which colour an opaque object appears to be is related to  the wavelengths of light that are transmitted through the objectthe intensity of light reflected from the objectthe wavelengths of light reflected by the objectthe brightness of the light absorbed by the object's surfacethe temperature of the objectthe frequency at which the object vibrates.
Visible light can be reflected, as seen in mirrors. When a surface is smooth, like a mirror, all the light is reflected in a single direction, known as  diffusespecularintegralopacitydifferentialeffervescent reflection. When a surface is rough, light is reflected in many different directions, known as  opacityspeculareffervescentdifferentialintegraldiffuse reflection.