Question

What element is `""^39"K"`?

Answer 1

Potassium

Explanation:

The element in a nuclide `(""_Z^YX)` is given by `X`, where `X` is the element's symbol on the periodic table.

So here, in the case of `""^39K`, the nuclide is potassium-`39`, and so the element is `K` or potassium.