alpha particle

noun

, Physics.

a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the nucleus of a helium atom.

alpha particle

a helium-4 nucleus, containing two neutrons and two protons, emitted during some radioactive transformations

alpha particle

A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by an atomic nucleus undergoing radioactive decay and is identical to the nucleus of a helium atom. Because of their relatively large mass, alpha particles are the slowest and least penetrating forms of nuclear radiation. They can be stopped by a piece of paper.
See more at radioactive decay

First recorded in 1900–05

Some particles — including protons, neutrons, alpha particles and beta particles — travel through space at high speeds.

Mercury 203 plus an alpha particle gives nice, stable Lead 207.

An alpha particle is the nucleus of a helium atom and is made up of two protons and two neutrons; it carries two positive charges.

There can thus be no doubt that the alpha particle becomes a helium atom when its positive charge is neutralized.

This stopping power of an atom for an alpha particle is approximately proportional to the square root of its atomic weight.

Ionium expels an alpha particle and becomes radium, which is a bivalent element resembling barium belonging to the second group.

April 19, 2024tortuous

[tawr-choo-uhs ]

Start each day with the Word of the Day in your inbox!

By clicking "Sign Up", you are accepting Dictionary.com Terms & Conditions and Privacy Policies.

Browse