Question

Which element releases electrons most easily (lowest ionization enthalpy)?

• A. Zinc
• B. Cadmium
• C. Mercury
• D. All equally likely

Hint:

Elements with lower ionization enthalpies tend to release electrons more easily, as less energy is needed to remove an electron.

Answer 1

The Correct Option is A

Ionization enthalpy measures how tightly an atom holds its outermost electron, the lower it is, the more easily that electron leaves. Among zinc, cadmium, and mercury, all group 12 metals with a filled d-subshell and two s-electrons on top, zinc is the one that lets go of its electron most easily, since mercury especially is pulled in tighter by relativistic effects. So zinc has the lowest ionization enthalpy, option (A).