Question

What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron

Answer 1

providing energy to an atom can allow the electron in its non valence shell to obtain energy and move to a higher energy orbital and act as a valence electron.

Step-by-step explanation:

Answer 2

Energy-

and it can be added to an atom to cause a non-valence electron in the atom to temporarily become a valence electron