# An atom of calcium has 20 protons, how many electrons does it have?

Mar 16, 2018

#### Answer:

Protons are massive, elementary particles with a unit POSITIVE CHARGE....

#### Explanation:

And so if we got a NEUTRAL calcium atom, if there are 20 positively charged particles, and there are, because, for calcium, by definition, $Z = 20$, there are NECESSARILY 20 negatively charged particles associated with the atom, that are conceived to whizz around the massive nuclear core.