Which of the following has the highest ionization energy? — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Ionization energy is the amount of energy required to remove an electron from a neutral gaseous atom. The trend of ionization energy decreases down the group due to an increase in atomic size and increases from left to right in periods due to the decrease in atomic size. In isoelectronic species, the element with a higher effective nuclear charge has higher ionization energy. Therefore, the Potassium ion K has the highest ionization energy.