Question

What is the name of the ion formed from FOUR `H^+` ions, equivalently bound to a `N^(3-)` ion?

Answer 1

You describe `"ammonium ion"`

Explanation:

And thus:

`NH_3 + H^(+) rarr NH_4^+`

Ammonium is a high symmetry species, and the hydrogens bound to the nitrogen centre are equivalent.