Question

the relationship bwtween frequency, wavelength, and speed holds for light waves because all forms of electromagnetic radiation travel at a single speed in a vaccum.

is this true??

or do different forms of electromagnetic radiation travel at different speeds?

Answer 1

The relationship between frequency, wavelength and speed holds for all wave motion, but the speeds differ with the situation and type of wave.

All electromagnetic waves IN A VACUUM travel at the same speed c, regardless of frequency.

Light can be slowed to very low speeds traveling through materials called Bose condensates. See
http://www.news.harvard.edu/gazette/1999/02.18/light.html