Final answer:
The 2p orbital in the periodic table is greatly shielded by the 2s orbital, reducing the effective nuclear charge experienced by the 2p electrons.
Step-by-step explanation:
The 2p orbital in the periodic table is greatly shielded by the 2s orbital. Shielding in chemistry refers to the ability of electrons in inner energy levels to partially block the attraction of the nucleus on outer electrons. In this case, the 2s electrons shield the 2p electrons from the full nuclear charge, reducing the effective nuclear charge experienced by the 2p electrons.
For example, in the second row of the periodic table, as we move from left to right, the effective nuclear charge increases. However, the electrons in the same principal shell are not very effective at shielding each other from the nuclear charge. This results in a decrease in the atomic size and an increase in the effective nuclear charge as we move from left to right across a period.
Therefore, the 2p orbital is greatly shielded by the 2s orbital in the periodic table.