Question

What is the relation between electron gain enthalpy and ionization energy?

• A. Electron gain enthalpy and ionization energy are inversely related; as one increases, the other decreases.
• B. Electron gain enthalpy and ionization energy are directly related; as one increases, the other increases.
• C. There is no direct relationship between electron gain enthalpy and ionization energy; they are independent properties.
• D. Atoms with high ionization energy generally have a high tendency to gain an electron (more negative electron gain enthalpy).

Answer 1

Answer: (D)

Atoms with high ionization energy generally have a high tendency to gain an electron (more negative electron gain enthalpy).

Answer 2

Both ionization energy (IE) and electron gain enthalpy (ΔH_eg) reflect an atom's attraction for electrons.

• IE: Energy required to remove an electron. High IE means the atom holds its electrons tightly.
• ΔH_eg: Energy change when an electron is added. A more negative ΔH_eg means the atom readily accepts an electron.

Relationship: Both properties generally increase across a period and decrease down a group. Therefore, atoms with high IE (difficult to remove electrons) tend to have a strong attraction for an additional electron, resulting in a more negative ΔH_eg.