Question

Least ionic character is found in
A. Mg
B. Sr
C. Ca
D. Ba

Answer 1

Hint: The amount of effort required to remove an electron from an atom is known as the ionisation energy. The atomic radius and the fundamental quantum number are related to the periodic table's ionisation energy trend. The distance between the outermost electrons and the nucleus increases as we travel down in the group due to the addition of more electron shells.

Complete Step by Step Solution:
The measure of the difficulty in removing an electron from an atom or ion is known as the ionisation energy. It can alternatively be described as an atom's or an ion's propensity to give up an electron.

Ionisation energy can be thought of as a measurement of the force that keeps the electrons where they belong. Since they are located in the atom's outermost orbit, the electrons in the valence shell are simple to remove.

As we descend in the group of Mg, Sr, Ca, Ra, additional energy levels are added, which causes the valence electrons to drift farther from the positive nucleus. As a result, there is less attraction between the Valence electrons and the nucleus. Moving from top to bottom in the group typically results in a drop in ionisation energy. This is due to decrease in the primary quantum number of the group's outermost electron.

The group ionic nature grows as we descend due to a decrease in ionisation energy.
So, the order of ionic nature is $Mg < Ca < Sr < Ra$.
Hence option A is correct.

Note: The removal of the electrons will be more challenging at high ionisation energies. The strength of the attraction between the positive nucleus and the negative electron determines the ionisation energy.