The symbol of the ion having 12 protons and 10 electrons would be Mg²⁺ , therefore the correct answer is option A.
<h3>What is the atomic number?</h3>
An atom's atomic number is determined by the total number of protons it contains. Both the number of neutrons and the number of electrons contained inside an atom have no connection to the atomic number.
We must determine the symbol for the ion with 12 protons and 10 electrons according to the problem.
As is well knowledge, the magnesium atom, symbolized by Mg2+, contains 12 electrons and 10 protons.
Thus, the correct answer is option a.
To learn more about the atomic number from here, refer to the link;
brainly.com/question/14190064
#SPJ4
