What is the composition of a helium atom emitted from the nucleus?

A helium atom, specifically the most common isotope known as helium-4, is composed of 2 protons and 2 neutrons. The protons are positively charged particles located in the nucleus and are responsible for the atomic number of helium, which is 2. The neutrons are neutral particles also found in the nucleus, contributing to the mass of the atom but not to its charge.

When a helium atom is emitted from the nucleus, such as in the process of alpha decay, it is often referred to as an alpha particle. This emission involves the loss of 2 protons and 2 neutrons from the original nucleus, resulting in the formation of a helium-4 nucleus. Understanding this composition is fundamental in nuclear physics and contributes to our knowledge of radioactive decay processes.