# An atom of a sodium has 11 protons, 11 electrons, 12 neutrons. What is its atomic number?

Mar 19, 2016

The atomic number, $Z$, is precisely the number of protons, positively charged, massive, nuclear particles, so $Z$ $=$ $11$.

#### Explanation:

The term we would use for this element is ""^23Na. If it is a sodium atom, then $Z$ $=$ $11$ by definition. If there are 11 protons, THERE MUST be 11 electrons orbiting around the atom, because the element here is NEUTRAL. If it is a ""^23Na nuclide, there must be 12 neutrons in the nucleus.

It would be worth your while to review these definitions. I appreciate that there are a lot of them, but atomic structure does make sense on the basis of neutrality, and the equality of positive and negative charges. If you're unsatisfied, state your objections, and someone will attempt to help.

Mar 19, 2016