Maybe it's best just to say H2.
No! Sh2!
No. Say: "the-one-with-only-one-proton-and-one-electron" just to be on the safe side. (Don't say atom--sounds too masculine.)
Boy I don’t know where to start here.
H is hydrogen, and IT is explosive. It is the one with 1 of each.
He is helium, which is NOT explosive.