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Difference between orbitals and shells

I don’t really understand the difference between them and I can’t seem to envision it

orbitals are the whole energy level in general, shells are like the paths in these orbitals. shells can only have two electrons, which travel in different directions. orbitals can have several shells, and the shells in that orbital are the same distance from the nucleus

Reply 2

Iqra_hussain216

Are they the circles that we would draw for gcse
As in when doing dot and cross diagrams a circle would be drawn to represent the electrons
Would that be the orbital? Or I’m I just confusing the two

Reply 3

Uori32qu

Original post by Iqra_hussain216

An orbital = a region that holds up to 2 electrons (never more than 2, but it can be 1 or 0). The 2 electrons are always of opposite spin. You can draw electrons as single-headed arrows in orbital boxes to show electron configuration.

The circles you draw (i.e. the Lewis model) for GCSE are not orbitals. They are the shells (or energy levels, which have a principal quantum number, n).

In the first shell (n=1), there is 1 orbital (called 1s) - this is why the first circle you drew for GCSE contained only 2 electrons.
In the second energy level (n=2) (or second circle at GCSE), you remember this holds 8 electrons, so there must be 4 orbitals - one 2s and three 2p orbitals - at this level.
Now, the third energy level (n=3) holds 18 electrons. This is why you can't use the GCSE version anymore. If it has 18 electrons, it must have 9 orbitals: these are one 3s, three 3p, and five 3d orbitals.

For each energy level, it is always the same pattern: one s orbital, three p orbitals, five d orbitals... (you shouldn't need to go higher than this)

What an orbital really is is simply a model for where there is a very high chance of an electron being. The 'shell' is just where there are lots of orbitals with the same/similar energy (e.g. 2s and 2p are close to each other in energy on an energy level diagram, while 1s is much lower energy).

Original post by Narr

Sorry but this is very wrong

Reply 4

Iqra_hussain216

Wow thank you so much I finally get it! :smile:

So the orbitals are the arrows drawn within that box and the box represents the shell
And there can only be a maximum of 2 electrons within that shell
And when drawing those circles for gcses, they were shells and between them represented the 1s,2s,3s etc
But what are sublevels
Are they within the orbitals?

Reply 5

Pigster

Original post by Iqra_hussain216

Wow thank you so much I finally get it! :smile:

I wouldn't say that, yet, if I were you.

"So the orbitals are the arrows drawn within that box and the box represents the shell"
The e- are represented by the arrows, not the boxes.
The boxes represent the orbitals.

"And there can only be a maximum of 2 electrons within that shell"
There is 1 box (orbital) in the 1st shell, holding 2 e- max. There are 4 boxes in the second shell (8 e-). At GCSE we simplify the 3rd shell and pretend that it also fills with 8 e- (actually it can hold more - 18, i.e. 9 orbitals (9 boxes)).
Orbitals can hold 2 e-, not shells (apart from the first shell, which only has 1 orbital).

"And when drawing those circles for gcses, they were shells and between them represented the 1s,2s,3s etc "
When drawing those circles for GCSEs, they were shells. But they did not represent 1s,2s,3s etc. At GCSE we draw shells as circles, but the e- only orbit the nucleus in circular paths (actually in 3D that would be spherical) in the 3 sub-shells, the p, d etc. have very much more complex paths.

"But what are sublevels"
Sublevels are the name given to groups of orbital types (i.e. s-type or p-type) that are similar, i.e. the 3x 4p orbitals are all similar and can be grouped together as a sub-shell. The 4p are different to 4d, so 4d are not in the 4p sub-shell. But, the 5x 4d orbitals are all similar, so are all grouped together in the 4d sub-shell.

"Are they within the orbitals?"
Subshells are made up of orbitals.