Atomic number of Alis 13 and mass number is 27 .Calculate the number of electrons protons and neutrons in the ion formed Represent the ion.What will be its valency?

Explanation

Atomic number of Ar= 13. Its electronic configuration is `{:(K,L,M),(2,8,3):}`
It loses 3: electrons, to complete its octet: Hence, the ion formed will be `Al^(3+)`.
Number of electrons in `Al^(3+)` = 13 -3 -10.
Number of protons in the ion = Atomic number 13.
Number of neutrons in the ion =Mass number - Atomic number = 27 - 13 =14.
As Al atom loses 3, electrons to complete its octet and form `Al^(+)` ion, its valency is 3.