K and L shell of an element are completely filled and there are 16 electrons in M-shell and 2-electr — Atomic Structure Chemistry Question

💡 Solution & Explanation

Let's sum the electrons in each shell to find the atomic number (Z) of the neutral element: K-shell (n = 1): completely filled, so it has 2 electrons. L-shell (n = 2): completely filled, so it has 8 electrons. M-shell (n = 3): contains 16 electrons (3s^2 3p^6 3d^8). N-shell (n = 4): contains 2 electrons (4s^2). Total number of electrons = 2 (K) + 8 (L) + 16 (M) + 2 (N) = 28 electrons. Therefore, the atomic number of the element is 28 (which is nickel).