what does helonium mean

Helonium is a cation (positively charged ion) with the chemical formula HeH+. It is also known as the helium hydride ion or hydridohelium(1+) ion. Helonium consists of a helium atom bonded to a hydrogen atom, with one electron removed. It can be viewed as protonated helium and is considered the lightest heteronuclear ion. This ion is believed to be the first compound formed in the Universe after the Big Bang. Helonium is highly reactive and cannot be prepared in bulk since it would react with any other molecule it contacts. It is known as the strongest acid, even stronger than fluoroantimonic acid.