Question

Manganese has a total of 25 electrons, but the following orbital notation for manganese is incorrect. Explain the error in terms of the rules for electron arrangements.

Manganese:

Answer 1

the 4s level is missing

Answer 2

Thank you. :)

Answer 3

4s fills before 3d. You can get that from the Madelung rules, or by looking at the Periodic Table. Since the s block lies at the left side of the Table, the s subshell always fills first. Then next block is the p block for Periods 2 and 3, so the 2p and 3p subshells come after the 2s and 3s, respectively. But when you get to Period 4, the d block comes between the s and p blocks, and that tells you the 3d subshell fills after the 4s, but before the 4p.