## unpaired electrons

Sarah Blake-2I
Posts: 153
Joined: Fri Aug 30, 2019 12:16 am

### unpaired electrons

How do we calculate the number of unpaired electrons after finding the electron configuration?

MAC 4G
Posts: 121
Joined: Wed Sep 18, 2019 12:16 am

### Re: unpaired electrons

After you find the electron configuration, you need to look at the orbital which comes last in the configuration that is being observed. It may be - s,p,d or f . The ‘s’ orbital contains max of 2 electrons whereas max electrons in p,d and f are 6,10 and 14. If the last orbital contains electrons less than the maximum number of electrons that should be present in an orbital then the difference of the maximum number of electrons which can be present in the subshell are subtracted with the electrons present in the last subshell of the electronic configuration.

For example- the electronic configuration of any element is “1s^2, 2s^2, 2p^5”

In this case 2p^5 is the last orbital of the electronic configuration then in this case the number of unpaired electrons are ‘1’ as p orbital contains maximum of 6 electrons and there are 5 electrons present in the orbital so the unpaired electrons are given by (6–5)=1.

Hope this helps.

Rida Ismail 2E
Posts: 139
Joined: Sat Sep 07, 2019 12:16 am

### Re: unpaired electrons

You need to follow Aufbau, Hund and Pauli principles to find the amount of unpaired electrons. You look for the outermost shell or the energy level and see how many electrons it constants. For the p orbital, if it contains 1 then there is 1 unpaired. If it contains 2 then there is 2 unpaired. If it contains 3 then there is 3 unpaired.
If it contains 4 then there is 2 unpaired. If it contains 5 then there is 1 unpaired. If it contains 6 then there is 1 unpaired. This is because the electrons want to occupy their own orbital before sharing with any other electrons, then they will share when all others are full.