Calculate the number of unit cells in 1 ~cm ^3 of an element if unit cell edge length is 2.0 10⁻⁸ ~cm

Step-by-step solution

The volume of a cubic unit cell with edge length a = 2.0 10⁻⁸ , cm is V = a^3 = (2.0 10⁻⁸)^3 = 8.0 10⁻²⁴ , cm ^3 . For a total volume of 1 , cm ^3 , the number of unit cells is N = 1 8.0 10⁻²⁴ = 0.125 10²⁴ = 1.25 10²³ . Matching with the given options, this corresponds to C .