How many unpaired electrons are in the ground state electron configuration for Mn?

Which of the following is a reasonable ground-state electron configuration?

• A.) 1s^2 1p^6 2s^2 2p^6 3s^2 B.) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 4d^8 C.) 1s^2 2s^2 2p^6 3p^6 D.) 1s^2 2s^2 2p^6 3s^1 Also can you please tell me why (I don't understand all that well ground-state electron configuration) other than it has to do with levels in which electrons are arranged in order to find their electron configuration (I guess order in which the electrons are arranged in an element). Thank You!

• Answer:

  A) is wrong because 1p6 does not existwith n =1 l has to be = only so only s orbital for n=1 Energy quantum state. B) is wrong because before filing 3d level 4s can be filled because it may have less energy, but $d cannot be filled before filling 3d or even 4p C) is wrong because because 3p has higher energy than 3s and cannot be filled first to make a ground state D)is correct because there is no objection Energy values of 3s> 2p>2s>1s