# How many protons are in the nucleus of an atom of oxygen?

The atomic number tells us how many protons are in the nucleus for any given element.

#### Explanation:

Oxygen is atomic number 8.

Therefore, its nucleus contains 8 protons.

Protons are positively charged. One proton has a charge of $+ 1$. In order for the atom to be in a neutral state, we need something to counter the charge of the proton. So we have electrons, which are negatively charged. One electron has a charge of $- 1$.

So the atomic number not only tells us the number of protons in an atom, but also the number of electrons.

Oxygen has 8 protons, and 8 electrons.