Question

question 20 of 25 what is the correct electron configuration for an element with 5 electrons in the 3d energy sublevel? a. 1s²2s²2p⁶3s²3p⁶3d⁵ b. 1s²2s²2p⁶3s²3p⁶3d⁶ c. 1s²2s²2p⁶3s²3p⁶4s²3d⁵ d. 1s²2s²2p⁶3s²3p⁶4s²3d⁶

Explanation:

Step1: Recall electron - filling order

Electrons fill orbitals in the order 1s, 2s, 2p, 3s, 3p, 4s, 3d, etc. The 4s orbital fills before the 3d orbital.

Step2: Calculate total electrons

We are looking for an element with 5 electrons in the 3d sub - level. The electrons before the 3d sub - level fill as follows: 1s has 2 electrons, 2s has 2 electrons, 2p has 6 electrons, 3s has 2 electrons, 3p has 6 electrons, and 4s has 2 electrons.

Step3: Write electron configuration

The electron configuration for an element with 5 electrons in the 3d sub - level is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{5}\).

Answer:

D. \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{5}\)