What happens to ionization energy as you move from left to right across a period on the periodic table?

As you move from left to right across a period on the periodic table, the ionization energy generally increases. This trend occurs because the number of protons in the nucleus increases as you move across a period, leading to a stronger positive charge that attracts the electrons more strongly. Consequently, it requires more energy to remove an electron from an atom.

Moreover, as the atomic radius decreases due to the increasing nuclear charge, the valence electrons are held more tightly to the nucleus. This decrease in distance also contributes to the higher ionization energy because the force of attraction between the positively charged nucleus and the negatively charged electrons becomes stronger.

Thus, this consistent increase in ionization energy across a period reflects the underlying changes in atomic structure and the forces at play between protons and electrons.