Final answer:
It is typically harder to remove a second electron compared to the first because the atom becomes a positively charged cation, increasing the electrostatic attraction. This trend is reflected in the increasing ionization energy required to remove successive electrons, with exceptions due to specific electron configurations.
Step-by-step explanation:
The typical trend for removing a second electron compared to removing the first is that it is harder to remove the second electron. This is due to the fact that when an electron is removed, the atom becomes a cation with a positive charge, and the increased electrostatic attraction makes it more difficult to remove additional electrons.
Successive ionization energies for a single element always increase; for instance, the first ionization energy is less than the second, which in turn is less than the third, and so on. A large increase in ionization energy occurs when core electrons are removed, as they are more tightly bound to the nucleus than the valence electrons.
There are exceptions to this trend based on electron configuration. For example, a decrease in ionization energy can occur when removing an electron makes the atomic structure more stable, such as when removing a paired electron from a p-orbital.
Additionally, the trend of increasing ionization energy is more apparent when moving diagonally from the lower left to the upper right of the periodic table. Group 2 elements, which have to lose two electrons to react, require more ionization energy for electron removal than Group 1 elements, which only lose one electron.