Question

which group of elements has the lowest ionization energies?
options:

• ali metals (group 1)
• halogens (group 17)
• noble gases (group 18)
• alkaline earth metals (group 2)

Explanation:

Ionization energy is the energy required to remove an electron from an atom. Alkali Metals (Group 1) have one valence electron, which is loosely held. They readily lose this electron, so they have the lowest ionization energy among the given groups. Halogens (Group 17) need one electron to complete their octet, so they have higher ionization energy than Group 1. Noble Gases (Group 18) have a stable octet, so they have very high ionization energy. Alkaline Earth Metals (Group 2) have two valence electrons, held more tightly than Group 1, so their ionization energy is higher than Group 1.

Answer:

A. Alkali Metals (Group 1)