Does the speed of light change for differenr types of Electromagnetic radiation?

Simple put no, and I believe (im not at all sure about this) that light is not electromagnetic radiation (I probably just made myself look very, very stupid but I do not do a lot of research into the light spectrum)

In empty space they all have the exact same speed c

in space (a vacuum)
the speed of all e-m waves is the same (c = 3.00E8 m/s)
but
in physical media different frequencies have different speeds
that's how a glass prism separates the spectral colors of white light

The speed of light at a given wavelength as it passes through a medium is dependent on the refractive index of the medium at that wavelength.

In vacuum, the refractive index is 1 for all wavelengths, so they all travel at the same speed, 3.0*10^m/sec

In glass, the refractive index is about 1.5, depending on the glass type and wavelength, so on average light will travel that much slower in glass.

Speed of light in glass = Speed of light in vacuum / refractive index

Now, in glass the refractive index generally varies slightly with wavelength, depending on the specific type of glass. So, the different wavelengths all travel at slightly different speeds. This change in speed as a function of wavelength causes white light to be split into the colors of the rainbow.

But it's not just glass. Electromagnetic energy passing through any transparent medium will be affected similarly. The speed of light passing through air, water, oil, etc, will vary based on the refractive index of the material. In fact, sice light is only one form of electromagnetic energy, other forms of electromagnetic energy such as infrared energy (heat), microwaves, light, ultraviolet radiation, x-rays, gamma rays, etc all behave similarly since the only difference between them all is their wavelength.

Hope this helps,

-Guru

The equation below is used for waves.
Velocity = Frequency * Wavelength

Go to the website below to
http://zebu.uoregon.edu/~imamura/122/images/electromagnetic-spectrum.jpg
Look at the graph. As you look from left to right, the wave length is getting shorter. The numbers for wave length go from 10^3 5 to 10^-5.
The numbers for the frequency go from 10^4 to 10^20.
As the wavelength decreases, the frequency increases; but the velocity remains constant.

The difference between each type of electromagnetic radiation is the energy.
 
Microwaves are used to heat up food. Infrared radiation is given off by warm objects. Visible light helps us see things. Ultraviolet radiation causes sun tan, and can cause skin cancer. X ? rays are used to see broken bones; and can cause cancer.
Gamma-rays can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells.

The velocity of all types of electromagnetic radiation is approximately 3 * 10^8 m/s.
The speed of light is much easier to say, than the speed of electromagnetic radiation! So that?s what we call it.
 3 * 10^8 m/s is the velocity when the waves are traveling through a vacuum, like outer space. When the waves travel through other substances, such as glass, the velocity is less than 3 * 10^8 m/s.