– Why are alpha- and beta radiation referred as particles, whilst gamma radiation as rays?

Question

– Why are alpha- and beta radiation referred as particles, whilst gamma radiation as rays?

In: Physics

Answer 1

Per Wikipedia:

> Alpha particles, **also called alpha rays** or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. ([source](https://en.wikipedia.org/wiki/Alpha_particle))

and

> A beta particle, **also called beta ray** or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. ([source](https://en.wikipedia.org/wiki/Beta_particle))

Finally, gammay rays consist of high-energy photons:

> A photon (from Ancient Greek φῶς, φωτός (phôs, phōtós) ‘light’) is an **elementary particle** that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. ([source](https://en.wikipedia.org/wiki/Photon))

Emphasis mine.

That said, alpha and beta rays are made from stuff we normally consider matter, whereas gamma rays are electromagnetic radiation, which we don’t. This could explain why it might be more common to emphasize the particle nature of alpha and beta radiation.