Helium hydride ion

The helium hydride ion, also called helonium, is a cation (chemical compound with a positive electric charge) made of helium and hydrogen. It has the chemical formula HeH⁺. It first formed shortly after the Big Bang, making it the oldest molecule in the universe.^[1]

Helium hydride is the strongest known acid. It cannot be made as a liquid or solid because it will react with any other molecule it touches.^[source?]

This short article about chemistry can be made longer. You can help Wikipedia by adding to it.

Sources

↑ Güsten, Rolf; Wiesemeyer, Helmut; Neufeld, David; Menten, Karl M.; Graf, Urs U.; Jacobs, Karl; Klein, Bernd; Ricken, Oliver; Risacher, Christophe; Stutzki, Jürgen (2019). "Astrophysical detection of the helium hydride ion HeH+". Nature. 568 (7752): 357–359. doi:10.1038/s41586-019-1090-x. PMID 30996316.

[1] Güsten, Rolf; Wiesemeyer, Helmut; Neufeld, David; Menten, Karl M.; Graf, Urs U.; Jacobs, Karl; Klein, Bernd; Ricken, Oliver; Risacher, Christophe; Stutzki, Jürgen (2019). "Astrophysical detection of the helium hydride ion HeH+". Nature. 568 (7752): 357–359. doi:10.1038/s41586-019-1090-x. PMID 30996316.

[1]