Question

What is the speed of light of alpha particle?

Answer 1

Alpha particles are relatively slow and heavy compared with other forms of nuclear radiation. The particles travels at 5 to 7 percent of the speed of light or 20,000,000 metres per second and has a mass approximately equivalent to 4 protons....

Answer 2

What do you mean by "light of alpha particles"?
Alpha particles do not emit light, only when accelerated.

Answer 3

Sorry I could not make out what is the meaning of Light of alpha particle, by the way alpha particles as I know are Helium nucleus with + 3.2 X [10^{-19} Coulomb charge