Solid AB has a rock salt type structure. If the radius of the cation is 200 pm, what is the maximum — Solid State Chemistry Question

💡 Solution & Explanation

In a rock-salt structure, the coordination number is 6 and the limiting radius ratio r_+ / r_- is [0.414, 0.732]. For the anion radius r_- to be maximum, we use the lower limit of the radius ratio: r_+ / r_- = 0.414 => r_- = r_+ / 0.414 = 200 / 0.414 = 483.1 pm.