AAMC FL Practice Exam

How does the ionization energy of metals compare to non-metals?

1. Metals have higher ionization energies

2. Metals have lower ionization energies

3. They have equal ionization energies

4. Non-metals are always easier to ionize

The correct answer is: Metals have lower ionization energies

The reasoning behind the choice that metals have lower ionization energies is rooted in the fundamental properties of these elements. Metals, which are generally located on the left side of the periodic table, have fewer valence electrons and are more inclined to lose electrons in order to achieve a stable electron configuration, often resembling that of noble gases. This tendency to lose electrons means that less energy is required to remove an electron from a metal atom, resulting in lower ionization energies. In contrast, non-metals, found on the right side of the periodic table, typically have more valence electrons and require additional energy to remove an electron. Non-metals are more likely to gain electrons to fill their outer shell, which explains why they exhibit higher ionization energies compared to metals. This distinction in ionization energy is reflective of the fundamental differences in reactivity and electron affinity between these two categories of elements, clarifying why the trend in ionization energy is consistent across the periodic table.