For instance, argon, krypton, and xenon form clathrates with hydroquinone , but helium and neon do not because they are too small or insufficiently polarizable to be retained. Helium He 2.

Oganesson Og is variously predicted to be a noble gas as well or to break the trend due to relativistic effects ; its chemistry has not yet been investigated. The Astrophysical Journal.

This process is environmentally-friendly: Igneous rock mass fraction in ppm [23]. Helium He 2.