Which statement best explains why ionization energy is opposite to atomic radius?

Which statement best explains why ionization energy is opposite to atomic radius?

• A. The smaller the radius, the weaker the attraction between nucleus and electrons.
• B. The smaller the radius, the closer electrons are to the nucleus and more strongly attracted, making removal harder.
• C. Ionization energy is independent of atomic size.
• D. Ionization energy depends only on the number of protons.

Answer: (B)

Ionization energy is the energy needed to remove an electron from a gaseous atom, while atomic radius is how far the outer electrons are from the nucleus. When the radius is small, the outer electrons sit closer to the positively charged nucleus and feel a stronger pull. That stronger attraction means it takes more energy to overcome it and remove an electron. If the radius is larger, the outer electrons are farther away and experience a weaker pull, so less energy is needed to pull one electron away. This inverse relationship is why the explanation that the smaller the radius, the closer the electrons are and the more strongly they are attracted, making removal harder, is the best choice.

Ionization energy is the energy needed to remove an electron from a gaseous atom, while atomic radius is how far the outer electrons are from the nucleus. When the radius is small, the outer electrons sit closer to the positively charged nucleus and feel a stronger pull. That stronger attraction means it takes more energy to overcome it and remove an electron. If the radius is larger, the outer electrons are farther away and experience a weaker pull, so less energy is needed to pull one electron away. This inverse relationship is why the explanation that the smaller the radius, the closer the electrons are and the more strongly they are attracted, making removal harder, is the best choice.