Calculate the coulombic force of attraction between ca2 + and o2 - in cao, which has the nacl-type structure

We determine the Coulombic force using the Coulomb's Law:

F = kQ₁Q₂/d²

where

k is equal to 9*10⁹ N·m²/C²

Q₁ and Q₂ are the charges of the two particles

d is the distance between them

For this problem, Q₁ = + 2 (0.16*10⁻¹⁸ C) and Q₂ = - 2 (0.16*10⁻¹⁸ C), because a single electron or proton has a charge of 0.16*10⁻¹⁸ C. The distance between the two ions is the sum of their radii.

d = radius of Ca²⁺ + radius of O²⁻

d = 0.106*10⁻⁹ m + 0.132*10⁻⁹ m

d = 0.238*10⁻⁹ m

F = (9*10⁹ N·m²/C²) (+2 (0.16*10⁻¹⁸ C)) (-2 (0.16*10⁻¹⁸ C)) / (0.238*10⁻⁹ m) ²

F = 1.017*10¹¹ N