Question

When an atom is charged, it is called an ion. How many electrons are in O^2-?

Answer 1

Answer:

10 electrons

Explanation:

Answer 2

O2- indicates an ion of oxygen having two extra electrons. I.e., since an oxygen atom normally has 8 protons and 8 electrons, this ion has 10 electrons (-10 charge) and 8 protons (+8 charge) giving it a charge of -2 (-10 + 8 = -2).