How do you write the noble-gas electron configuration for manganese?

1 Answer
Aug 7, 2018

Answer:

Well, #Z_"manganese"=25#...#Mn-=[Ar]4s^(2)3d^5#

Explanation:

...the nearest Noble gas is #"argon, Z=18"#..

And so we do not have to specify the configuration of the first 18 electrons, because these approximate the configuration of argon..

#underbrace(Z=18, 1s^(2)2s^(2)2p^(6)3s^(2)3s^(6))_"electronic configuration of argon"#

For manganese, #Z=25#

#underbrace(Z=25, 1s^(2)2s^(2)2p^(6)3s^(2)3s^(6))_"electronic configuration of argon"4s^(2)3d^5#

And so finally...#Mn-=[Ar]4s^(2)3d^5#

And clearly all the chemical action takes place with the valence electrons...