## Building Up

Marty Hockey
Posts: 47
Joined: Wed Sep 18, 2019 12:19 am

### Building Up

What is the purpose of writing the electron structure of carbon as 1s^2 2s^2 2px^1 2py^1 as opposed to 1s^2 2s^2 2p^2?

DarrenKim_1H
Posts: 123
Joined: Fri Sep 20, 2019 12:17 am
Been upvoted: 1 time

### Re: Building Up

According to Hund's rule, electrons repel each other in the same subshell which is why they must occupy different orbitals with parallel spin

Jessica Castellanos
Posts: 102
Joined: Sat Aug 24, 2019 12:17 am
Been upvoted: 1 time

### Re: Building Up

This is actually due to Hund's rule to be more specific about where the electrons in the p orbital would be. Since there are two electrons in the p orbital in your example, they would not both be in the same orbital because that would increase the energy and the lowest energy possible would be with one electron in the 2px orbital and one in the 2py orbital with parallel spins, so writing it as 2px^1 2py^2 specifies the orbitals in which the electrons would be. Hope this helps!