Helium atoms are the second lightest and second most abundant element in the universe, represented by the symbol He. Each helium atom consists of two protons, two neutrons, and two electrons. This simple structure makes helium a noble gas, meaning it is chemically inert and does not easily react with other elements. Helium is commonly found in natural gas deposits and is produced through the nuclear fusion processes in stars. It is well-known for its use in balloons, as it is lighter than air, and in scientific applications, such as cryogenics, due to its low boiling point.