Figure 7.2 depicts the interactions of an ion with its first nearest neighbors, second nearest neighbors, and third nearest neighbors in a lattice.

Figure 7.2

 

(a) Would the interactions with the fourth nearest neighbors be attractive or repulsive?

(b) Based on Coulomb’s law, how would the relative sizes of the terms compare if the potential energy were expressed as V = V_1st + V_2nd + V_3rd + V_4th?

Transcribed Image Text:

Potential energy (kJ/mol) -432 The amount by which the energy is lowered by this interaction is called the bond energy. 4 When the atoms are pushed too close to each other, the nuclei start to repel each other. There is a dramatic increase in the potential energy as a result. 0 HH HH 0.074 H H 1 When widely separated, atoms do not interact with each other at all, so the potential energy is zero. As atoms approach each other they begin to interact and the 2 potential energy decreases. Attractive interactions lower the potenial energy. Internuclear distance (nm) (H-H bond length) 3 When the atoms reach an optimal separation, there is significant sharing of electrons between the two nuclei. This distance lowers the potential energy more than any other and is called the equilibrium bond length. H H