Describe the changes in electronic configurations when magnesium reacts with sulfur to form the ionic compound MgS. Show the changes on the ions
Answers
[Ne] 3s² 3p⁴
Ato. of electron in 1st orbit = 2 ( Max. Capacity is 2 )
No. of electron in 2nf orbit = 8 ( Max. Capacity is 8 )
No. of electron in 3rd orbit = 16-(2+8) = 6 ( Max. Capacityis 8 )
1st orbit has only 1s orbital. So, electronic configuration is 1s² .
2nd orbit has 2s and 2p orbitals. As we know s orbital can hold max. 2 electrons and p orbital can hold max. 6 electron so, the configuration is 2s² 2p6 .
3rd orbit has 3s, 3p and 3d orbitals. As Energy of 3s < Energy of 3p < Energy of 3d So, 3s is filled at first followed by 3p and 3d as per Aufbau's rule. So, electronic configuration is 3s² 3p⁴. As all the electrons are accommodated with in 3p so, 3d will remain empty. Moreover, in 3p orbital all the 3 degenerated orbitals get 1 electron at first and then pairing occurs according to Hunds' rule.
So, final electronic configuration of Sulphur is
1s² 2s² 2p6 3s² 3p⁴