Question

Compare the radii of two species X and Y. Give reasons for your answer.

1. X has 12 protons and 12 electrons
2. Y has 12 protons and 10 electrons

Answer 1

In the two given options, species X and Y represents the same element magnesium. X is magnesium atom and Y is magnesium ion. Out of Mg and Mg²⁺ ion Mg atom would be larger as the number of energy shells in Magnesium atom is three while the number of energy shells in magnesium ion is two.