Answer:
8 electrons (e-)
Explanation:
In the atom of every elements, there are three sub-atomic particles namely: protons, electrons, and neutrons. The protons are the positively charged particles, the electrons are negatively charged while the neutrons are neutrally charged.
In an uncharged or neutral atom i.e. charge 0, the number of protons is always equal to the number of electrons because they cancel each other out. When a difference occurs in the number of these particles, the atom becomes charged i.e. an ion. According to this question, oxygen atom (O) contains 8 positively charged protons, this means that it also contains 8 negatively charged electrons in its atom.
