The reactivity of an atom arises from

a. The number of electrons in the nucleus.
b. The number of protons in the nucleus.
c. The number of electrons in the valence shell.
d. The atomic mass.

Respuesta :

Answer:

C. The number of electrons in the valence shell

Explanation:

When the valence shells are complete, the atom is unreactive. However, when they are incomplete, they are chemically reactive.