Question

When an electron is added to the neutral isolated atom, energy is given out. It is an exothermic process. In this process, monoanion is formed. Electron affinity of an element is defined as the amount of energy liberated when an electron is added to the neutral isolated atom in its ground state. Greater the amount of energy released, greater is the electron affinity. Electron affinity is expressed in terms of $eVato{m}^{-1}$ or $Kcal$ or $kJmo{l}^{-1}$.

Electron affinity of elements depends on which of the following?

• A. Atomic size
• B. Nuclear charge
• C. Configuration
• D. Chemical environment

Answer 1

Answer: (A), (B), (C)

Configuration

Electron affinity of an element is defined as the amount of energy liberated when an electron is added to the neutral isolated atom in its ground state.
Electron affinity depends on the atomic size of the element. Greater the atomic size, lesser is the electron affinity.
Also, if the nuclear charge is more, then the incoming electron will experience a greater attractive force and thus the electron affinity will be high.
Also, the elements having half filled and completely filled orbitals(electronic configurations) are more stable, hence have the less electron affinity.