Shielding Effect

[Valerie Doan 3I]

This is part of a homework question from the textbook that my TA went over, but I still don't understand it.

Why are electrons in an s orbital more effective at shielding from the nuclear charge than p orbitals?

[Lillian Ma 1I]

The shielding effect happens when inner e- shield outer e- from electrostatic attraction of the positive nucleus. Therefore the further away the electrons are, like they are in p-orbitals, the less they are able to shield other electrons.

[Lucy_Balish_3G]

What helped me most understand shielding was the example of people standing around a fire pit. Those closest to it block you from some of the heat, but you can still feel the warmth of it even if there are people standing between you and the fire. So because s-orbital electrons are closer to the nucleus (the fire) they have a greater effect on shielding than those in the p-orbitals which are further away.

[Crystal Pan 2G]

Lucy's analogy of people standing around the fire pit is a good example! Since s-orbitals are closer to the nucleus, they are more effective at shielding.

[VincentLe_3A]

Electrons in the p-orbital are further away from the nucleus compared to those in the s-orbital. Therefore, since they are closer to nucleus, the inner electrons in the s-orbital shield the nuclear charge from the outer atoms in the p-orbital, since the attraction is more directed towards the closer inner electrons.

[Valerie Doan 3I]

Thanks for the explanation guys! But, what about the shielding effects of s and p orbitals with different principle quantum numbers? For example, if we compare a 2p orbital and a 3s orbital, is a 2p orbital more effective at shielding? Or is it in general s-orbitals are more effective at shielding no matter its principle quantum number?

[Neha Gupta 2A]

I think the s orbital generally shields better since those electrons are closest to the nucleus and bear the brunt of its charge.