Which factor increases ionization energy?

Which factor increases ionization energy?

• A. Distance from nucleus
• B. Nuclear charge
• C. Shielding effect
• D. Atomic radius

Answer: (B)

Ionization energy measures how strongly the nucleus pulls on its electrons. The factor that increases this energy is the nuclear charge: more protons in the nucleus create a stronger positive pull on the electrons, so more energy is required to remove one. Distance from the nucleus, shielding by inner electrons, and a larger atomic radius all work in the opposite direction. If electrons are farther away, the nucleus’s pull is weaker; shielding reduces the effective nuclear charge felt by the outer electrons; and a bigger atomic radius means the valence electron sits farther from the nucleus. All of these tendencies lower the energy needed to remove an electron. So the strongest factor that raises ionization energy among the options is the nuclear charge.

Ionization energy measures how strongly the nucleus pulls on its electrons. The factor that increases this energy is the nuclear charge: more protons in the nucleus create a stronger positive pull on the electrons, so more energy is required to remove one.

Distance from the nucleus, shielding by inner electrons, and a larger atomic radius all work in the opposite direction. If electrons are farther away, the nucleus’s pull is weaker; shielding reduces the effective nuclear charge felt by the outer electrons; and a bigger atomic radius means the valence electron sits farther from the nucleus. All of these tendencies lower the energy needed to remove an electron. So the strongest factor that raises ionization energy among the options is the nuclear charge.