Potassium fluoride (KF) is a molecule formed by an ionic bond. At equilibrium separation the atoms are \(r_{0}=0.255 \mathrm{nm}\) apart. Determine the electrostatic potential energy of the atoms. The electron affinity of \(F\) is 3.40 \(\mathrm{eV}\) and the ionization energy of \(\mathrm{K}\) is \(4.34 \mathrm{eV}\). Determine dissociation energy. (Neglect the energy of repulsion.)

Coulomb’s law is a fundamental principle that describes the electrostatic interaction between electrically charged particles. It states that the force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

The formula for Coulomb’s law is given by: \[ F = k_{e} \frac{|q_1 \cdot q_2|}{r^2} \]where \( F \) is the magnitude of the electrostatic force between the charges, \( k_{e} \) is Coulomb's constant, \( q_1 \) and \( q_2 \) are the magnitudes of the charges, and \( r \) is the distance between the centers of the two charges.

In our exercise, we observe Coulomb's law applied to calculate the electrostatic potential energy between the potassium ion (K+) and the fluoride ion (F-). Since these ions have opposite charges, the resulting force and therefore the potential energy is negative, indicating that they attract each other.

Dissociation energy refers to the amount of energy required to break a chemical bond and separate atoms in a molecule or ionic compound into individual ions or gaseous atoms. For an ionic compound like potassium fluoride (KF), the dissociation energy encompasses the energy required to overcome the electrostatic forces holding the ions together.

In the context of the provided exercise, the dissociation energy is calculated by considering the ionization energy of potassium (i.e., the energy required to remove an electron from a neutral potassium atom), the electron affinity of fluorine (i.e., the energy released when an electron is added to a neutral fluorine atom), and the electrostatic potential energy calculated using Coulomb's law. The resulting dissociation energy gives us the amount of energy that needs to be introduced to the KF molecule to cause it to dissociate into its constituent ions.

Ionic bonds are a type of chemical bond formed between two ions with opposite charges. This occurs when one atom donates an electron to another, resulting in a positively charged ion (cation) and a negatively charged ion (anion). The electrostatic attraction between these oppositely charged ions creates the ionic bond.

In potassium fluoride (KF), the potassium atom loses an electron to become a K+ ion, while the fluorine atom gains an electron to become an F- ion. The attraction between K+ and F- ions is the ionic bond that holds the compound together. The strength of an ionic bond is related to the charge of the ions and their separation distance; as Coulomb's law indicates, greater charges and smaller distances increase the force of attraction which can also be viewed in terms of potential energy. Therefore, understanding ionic bonds is essential not only for predicting the properties of ionic compounds but also for calculating their electrostatic potential energies as part of a comprehensive exploration of chemical energetics.