Which of the following has the highest first ionization potential: K,Ge,Kr,Ca,Br?
A)K
B)Ge
C)Kr
D)Ca
E)Br

Question

Quizplus · Accepted Answer

First ionization potential is the energy required to remove one electron from a neutral atom in the gaseous state. As we move across a period, the first ionization potential increases due to increase in the nuclear charge which exerts a stronger force on the valence electrons, making them more difficult to remove. Among the given options, Kr is the element in the rightmost position of the period which means it has the highest nuclear charge and hence, the highest first ionization potential. Therefore, the correct answer is C) Kr.

Which of the Following Has the Highest First Ionization Potential