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

Step 1: Understanding ionization enthalpy.
Ionization enthalpy refers to the energy required to remove an electron from an atom in its gaseous state. The lower the ionization enthalpy, the more easily an element releases an electron.
Step 2: Comparison of elements.
- Zinc (Zn) is in Group 12 of the periodic table and has a relatively low ionization enthalpy compared to other elements listed. - Cadmium (Cd) and Mercury (Hg), being heavier transition metals, have higher ionization enthalpies than Zinc.
Step 3: Conclusion.
Thus, Zinc releases electrons most easily, corresponding to option (A).

Answer 2

Step 1: Ionization enthalpy is the energy needed to pull an electron away from an atom — the lower it is, the more easily the atom gives up an electron.

Step 2: Among Zn, Cd, and Hg, Zinc is the lightest and has the lowest ionization enthalpy of the three.

Step 3: Cadmium and Mercury, being heavier, hold their electrons more tightly.

Step 4: So Zinc releases its electron most easily — option (A).

Answer 3

Elimination approach: Going down a group, ionization enthalpy usually falls because the outer electron sits farther from the nucleus. Zinc is the lightest and topmost of the three, which would normally make it hold its electron more tightly, but mercury's outer electron is pulled in unusually close by relativistic effects, making mercury surprisingly hard to ionize, and cadmium sits between the two. Comparing all three this way, zinc turns out to be the one that lets go of an electron most easily, option (A).