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### Electron Configurations

Posted: Tue Oct 22, 2019 10:42 pm
Hi can somebody please explain to me how you know the order when writing an electron configuration? For example, 1s, 2s, 2p....Is there a trick to remember the order? Also, how do you know how many electrons will fit in that orbital? Let me know if I have to clarify any parts of the question. Thank you :)

### Re: Electron Configurations

Posted: Tue Oct 22, 2019 10:45 pm
Hello, so if we were to google the "electron configuration" there is a chart that we go by with arrows, but this is the more tedious and often confusing method to understand this. Generally the best way to understand this is all elements in groups 1-2 are s, all elements in groups 13-18 are p, all elements from 3-12 are d, and all elements from 57-80 along with 89-112 are f. Hope this helps!

### Re: Electron Configurations

Posted: Tue Oct 22, 2019 11:00 pm
As to your question on how many electrons will fit into a specific orbital, each orbital consists of two electrons. There is one s-orbital, thus there are 2 electrons in the s-sublevel. There are 3 p-orbitals, thus there are 6 electrons in the p-sublevel (3 p-orbitals* 2 e- per orbital). There are a total of 5 d-orbitals, thus there are 10 electrons in the d-sublevel. There are a total of 7 f-orbitals, thus there are 14 electrons in the f-sublevel.

### Re: Electron Configurations

Posted: Wed Oct 23, 2019 11:17 am

### Re: Electron Configurations

Posted: Wed Oct 23, 2019 12:29 pm
When looking at the periodic table, you kinda just go left to right and then down to the next row. The first two elements of each row on the left will be s, and the last 6 of the row are going to be p (except for the first row which is just 1s2 in total). You just go 1s2,2s2,2p6,3s2,3p6,... and so forth :) but then after the 3rd row, you'll also hit the d-block, which goes up to xd10 (x being row number-1).