what does electromagnetic waves travel at a speed of?

Question

anonymous · Answer

at a constant speed of 3x10^8 m/s.

anonymous · Answer

same as the speed of light.

anonymous · Answer

yes light is an electromagnetic wave

anonymous · Answer

It is a transverse wave.Electromagnetic information about the charge travels  "at the speed of light" .Electromagnetic radiation may behave either as a wave or as particles.
 (1) As a wave, it is characterized by the speed of light, wavelength, and frequency. 
(2) When considered as particles ( photons), each has an energy related to the frequency of the wave given by
 Planck's relation 
                                E = hν

anonymous · Answer

excellently elaborated!

radar · Answer

Wouldn't the wave's velocity depend on the medium?  A electromagnetic wave bends (refracts) passing through the various layers of our ionospheres, isn't this due to velocity changing?  Same as light entering water???  Inquiring minds want to know!

anonymous · Answer

the velocity changes but by a little amount causing a bent when passing through a medium.

radar · Answer

Is it possible to increase this velocity?