Tags: Chemical Compound, Chemical Substance.
This article is about the physics of atomic helium. For other properties of helium see helium.A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with either one or two neutrons depending on the isotope held together by the strong force. Unlike for hydrogen a closed-form solution to the Schrödinger equation for the helium atom has not been found.