Which of the follow has the highest ionization energy?
a.
alkaline metal
b.
halogens
c.
transition metal
d.
noble gases
The correct answer is d. noble gases.
Noble gases have the highest ionization energy because they have a full valence shell of electrons, making it difficult to remove an electron. Alkaline metals have the lowest ionization energy because they have only one valence electron, which is easily removed. Halogens have a high ionization energy because they are close to having a full valence shell and are highly reactive. Transition metals have varying ionization energies depending on their electron configuration.