Question

What are some examples of alpha particles?

Answer 1

Hint: The radioactive decay of any radioactive species emits various particles called radioactive particles. Alpha, beta, gamma particles are examples of such particles. Alpha particle is a radioactive particle having a positive charge. They are generally the helium nucleus.

Complete answer:
Radioactivity is the phenomena of emitting radioactive rays. Alpha particle is one of the radioactive rays. An alpha particle is a positively charged particle that has a high ionization power and it is less penetrating.
Alpha decay is the process that produces alpha particles. The large radioactive nuclides, such as uranium, thorium, radium, undergoes decay, which decreases their mass number by 4 units, resulting in creation of alpha particles. Since, alpha particles have a mass of 4, they are the nucleus of the helium atom.
An alpha particle does not contain any electron, it has only protons and neutrons, and therefore it is termed as the helium nucleus. This is the only example of alpha particles. The reaction, that explains the formation of an alpha particle (helium – 4 nucleus) is:
$\begin{align}
  & {}_{92}^{235}U\to {}_{2}^{4}He+{}_{90}^{231}Th \\
 & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\alpha \\
 & \,\,\,\,\,\,\,\,\,\,\,\,\,\,particle \\
\end{align}$
The reaction shows uranium undergoes alpha decay to form a helium atom, which is an alpha particle and thorium.
Hence, an alpha particle has only one example which is the helium nucleus, ${}_{2}^{4}He$.

Note:
The alpha decay that creates an alpha particle or the helium nucleus is a type of nuclear fission, where a nucleus of a larger radioactive element, undergoes decay to form 2 particles, one alpha – particle, or helium nucleus and other is the lighter radioactive element.