Question

The relationship between the electron affinity of a univalent cation such as Na${}^{+}$ and the ionisation energy of the neutral atom is:

• A. $\left(IE\right)=-\left(EA\right)$
• B. $\left(IE\right)=-3\left(EA\right)$
• C. $\left(IE\right)=-2\left(EA\right)$
• D. None of these

Answer 1

Answer: (A)

$\left(IE\right)=-\left(EA\right)$

$N{a}^{+}\left(g\right)+e^{-}\to Na\left(g\right)$ $\Delta H=-\left(EA\right)$

$Na\left(g\right)\to N{a}^{+}\left(g\right)+e^{-}$ $\Delta H=+\left(IE\right)$

$\therefore \left(IE\right)=-\left(EA\right)$

Hence, option A is correct.