The distance between a Mg²⁺ ion with a charge of 3.2x10^–19 C and a Cl^- ion with a charge of –1.6x10^–19 C is 2.53 pm. What is the amount of work needed to make the distance between the two ions an infinite distance? 

The combination of cations and anions in the gas phase releases a lot of energy due to the stabilization of ions. Arrange the following gas-phase ion pairs in ascending order based on how much energy they release when they form.

Li⁺Br^–, K⁺S^2–, Ca²⁺Cl^–, Al³⁺O^2–, Ba²⁺O^2–

Rank the following interactions between charged particles from lowest to highest potential energy based on Coulomb's law.

(i) a 1+ charge and a 1− charge with a 117 pm distance between them

(ii) a 2+ charge and a 1− charge with a 119 pm distance between them

(iii) a 1+ charge and a 2− charge with a 117 pm distance between them

(iv) a 2+ charge and a 2− charge with a 119 pm distance between them