Which radiation travels the fastest at 90% of the speed of light?

Gamma radiation travels at the speed of light, making it the fastest of the listed forms of radiation. It is an electromagnetic wave, which allows it to move through a vacuum at this constant high speed. In contrast, alpha particles, which are composed of two protons and two neutrons, and beta particles, which are high-energy, high-speed electrons or positrons, both travel at velocities lower than the speed of light.

Muons are heavier cousins of electrons and, while they can travel at significant speeds, they too do not reach the speed of light. In fact, none of the particles listed can surpass the speed of light, which is a fundamental principle of physics.

The statement about beta radiation, which is often associated with speeds up to 90% of the speed of light, refers to specific conditions when beta particles are emitted from certain radioactive processes. However, the maximum theoretical speed of these particles would still not reach the full speed of light. Hence, it is incorrect to say that beta radiation travels at 90% of the speed of light in a definitive sense compared to gamma radiation, which consistently travels at this maximum speed.

Thus, gamma radiation is the fastest among these types of radiation, while beta radiation is a mischaracter