Chapter 3, Problem 64E

Interpretation Introduction

Interpretation: The electron affinity of fluorine and ionization energy of sodium is to be compared. The sign of $\Delta E$ in the process of electron “pull” from the sodium atom to the fluorine atom is to be evaluated. The reason of stability of $\text{NaF}$ compound is to be explained. The sign of $\Delta E$ in the overall formation of $\text{NaF}$ is to be evaluated.

Concept introduction: The change in energy of a reaction is defined as the sum of change in the internal energy of a system and the product of its absolute temperature and entropy.

Electron affinity is defined as the energy released from a neutral atom in gaseous phase when it gains an electron to form negatively charged ion.

Ionization energy is defined as the energy required to remove an electron from the neutral atom.

To determine: The analogy between the electron affinity of fluorine and ionization energy of sodium; if the $\Delta E$ is positive or negative in the process of electron “pull” from the sodium atom to the fluorine atom; the reason that the $\text{NaF}$ compound is stable; if the $\Delta E$ is positive or negative in the overall formation of $\text{NaF}$.