Helium (after Helios, the Greek sun god) is a chemical element (atomic number 2). It is a gas at most pressures and temperatures, with a boiling point of just above absolute zero. Although it is the second most abundant element in the universe (after hydrogen) it is fairly rare on earth, being found in some natural gas formations. Most helium on earth is the result of radioactive decay of heavier elements, such as uranium. It was one of the last common elements to be isolated, not being formally identified and named until 1895.
Helium is the lightest of the inert gases. Under normal conditions, it will not form chemical compounds with other elements, although it will do so under very high heat and pressure.