## Difference between the electron shell and orbitals

Laura WM 3I
Posts: 31
Joined: Wed Sep 18, 2019 12:19 am

### Difference between the electron shell and orbitals

What is the relationship/difference between electron shells and orbitals?

JOtomo1F
Posts: 66
Joined: Sat Aug 24, 2019 12:16 am

### Re: Difference between the electron shell and orbitals

Each electron shell is divided into subshells which are made up of orbitals. Each orbital is named by a letter (s-, p-, d-, f-) and hols electrons with up and down spins.

Connor Ho 1B
Posts: 102
Joined: Sat Aug 17, 2019 12:17 am

### Re: Difference between the electron shell and orbitals

Electron shells are defined by the energy level, n=1, n=2, n=3. Orbitals are the combination of details between the energy level and the "subshell" or the "shape" of the electron cloud.

For example, an orbital is energy level + subshell, so 4d, 3s, 1s, 2s, etc. are all orbitals. Electron shells are one of the two details needed to define an orbital, from what I understand.

Andrew Pfeiffer 2E
Posts: 101
Joined: Sat Sep 28, 2019 12:16 am

### Re: Difference between the electron shell and orbitals

As succinctly as I can put it, electron shells are made up of orbitals that have the same principal quantum number (n). Orbitals are regions around the nucleus of an atom where one is most likely to find a corresponding electron.

Hope this brief distinction helped!

Sean Cheah 1E
Posts: 105
Joined: Wed Sep 18, 2019 12:20 am

### Re: Difference between the electron shell and orbitals

All the answers above me are close but just ever so slightly off. While it is true that each shell contains one or more orbitals, it is not entirely correct to say that each angular momentum quantum number l represents an orbital within a given shell with principal quantum number n. This becomes obvious when you remember that the angular quantum number is only allowed to take on whole number values from 0 to n-1. As an example, if we were to look at the shell given by n=2, l can be any whole number from 0 to 1. If each value of l did directly correspond one-to-one with an orbital, this would suggest that there are only 2 orbitals (l=0 and l=1) within the second energy level. Considering the fact that each orbital can hold a maximum of two electrons, you might then think that the second energy level can only hold a maximum of 2*2 or 4 electrons, which is completely nonsensical seeing as Ne in its ground state has 8 electrons in its second shell (electronic configuration: 1s2 2s2 2p6).

If one wanted to know the number of orbitals within a specific energy level, they'd have to go one step further and look at the magnetic quantum number $m_{l}$, which can take on any integer values from -l to l. Going back to our example for n=2 and $0\leq l\leq 1$, that would mean that $-1\leq m_{l}\leq 1$ for l=1 and $m_{l}=0$ for l=0. Counting up all the possible values for $m_{l}$ yields 4, the exact amount of orbitals needed to hold the 8 electrons that we expected to be within the second shell.