He4 (Helium-4)

Helium-4 (^4He) is a stable isotope of helium, consisting of two protons and two neutrons in its nucleus. It is the most common form of helium found naturally, especially after hydrogen in the universe. Helium-4 is produced through nuclear fusion in stars and is also used in various applications like cooling superconducting magnets, inflating balloons, and scientific research. Its atomic structure makes it inert and non-reactive, and it remains a gas at very low temperatures, turning into a liquid or solid only under extreme conditions.