Question

What electrons would best shield an electron in the 2p orbital?

is it possible for electrons in a 4s orbital to partially shield an electron in the 2p orbital?

Answer 1

Shielding : Inner orbital electrons cause Less experience of the nucleus on the outer orbital electrons.

For 2P electrons the inner orbit electrons are only 1S electrons will shield the 2p electrons.

Answer 2: Only inner orbital electrons shield the outer orbital electrons cause less experience of nucleus on the outer most electrons.

Yes 2P electrons can shield outer orbit electrons (4S electrons). Due to the shielding effect of inner orbit electrons 4s electrons can be removed easily from the neutral atoms in gaseous State.