Answer: The correct answer is : The maximum amount of electrons that can be in a given layer is given by 2n ^ 2,
2n ^ 2 = 32
n ^ 2 = 32/2
n ^ 2 = 16
therefore, n = 4
Explanation: 2n ^ 2 means that in the first layer 2 electrons can fit with n = 1, in the second layer they fit 8 electrons with n = 2, in the third they fit 18 electrons with n = 3 and in the fourth layer they fit 32 electrons with n = 4