Understanding Electron Shells: Defined by Principal Quantum Number

[ldv1452]

What would be the best way to define electron shell? I know that it is identified by the principal quantum number, but not sure how to clearly define it.

 

[stewartcs]

What would be the best way to define electron shell? I know that it is identified by the principal quantum number, but not sure how to clearly define it.

It essentially represents the energy level of an electron IIRC.

CS

 

[ldv1452]

It essentially represents the energy level of an electron IIRC.

CS

Are electrons in the same shell all roughly the same distance from the nucleus then?

 

[alxm]

Are electrons in the same shell all roughly the same distance from the nucleus then?

Not really; because the different orbitals have such quite different geometries. If you compare s-orbitals with s-orbitals or p-orbitals with p-orbitals their distance from the nucleus increases as the shell does.

 

[ldv1452]

Not really; because the different orbitals have such quite different geometries. If you compare s-orbitals with s-orbitals or p-orbitals with p-orbitals their distance from the nucleus increases as the shell does.

So is that saying that if you compare s-orbitals with p-orbitals that may not hold true? For example, could you have an electron in a p-orbital of the 2nd shell with a higher energy level and/or further distance from the nucleus than that of an electron in the s-orbital of the 3rd shell?

 

[alxm]

So is that saying that if you compare s-orbitals with p-orbitals that may not hold true? For example, could you have an electron in a p-orbital of the 2nd shell with a higher energy level and/or further distance from the nucleus than that of an electron in the s-orbital of the 3rd shell?

No, but for instance, if one looks at the radial density distribution, the 2s orbital has its maximum farther out than the 2p orbital. 3d is farther in than 3p, but on the other hand, 3d is a lot more diffuse. (1s, 2p, 3d, 4f have no radial nodes and are therefore more diffuse).