Question

A radioactive source emits three types of radiations.Name the radiation which travels with the speed of light.

• A. Gamma
  
• B. Alpha
• C. Beta
• D. None of these
  

Answer 1

Answer: (A)

Gamma

The speed of light $c=3\ast {10}^{8}m/s$

$\alpha$ rays are $H{e}_2^4$ and $\beta$ rays are $e^{-}$(excited) so both have mass and both are particle waves while $\gamma$ rays don't have mass so these are electromagnetic waves and we know electromagnetic waves travels with the speed of light.