Regarding distance from the nucleus, which statement is correct?

Regarding distance from the nucleus, which statement is correct?

• A. Distance has no effect on ionization energy
• B. Closer electrons are easier to remove
• C. Closer electrons are harder to remove
• D. Distance only affects shielding

Answer: (C)

The binding energy of an electron depends on how far it is from the nucleus: the closer an electron is, the stronger the Coulomb attraction pulling it in. Because the nucleus pulls more powerfully on nearby electrons, more energy is needed to pull a close electron away. In atoms with several electrons, inner electrons sit nearer the nucleus and are shielded less, so they’re bound even more tightly; outer electrons sit farther out and are shielded by the inner electrons, making them easier to remove. So the statement that closer electrons are harder to remove is the correct reflection of how distance from the nucleus influences ionization energy.

The binding energy of an electron depends on how far it is from the nucleus: the closer an electron is, the stronger the Coulomb attraction pulling it in. Because the nucleus pulls more powerfully on nearby electrons, more energy is needed to pull a close electron away. In atoms with several electrons, inner electrons sit nearer the nucleus and are shielded less, so they’re bound even more tightly; outer electrons sit farther out and are shielded by the inner electrons, making them easier to remove. So the statement that closer electrons are harder to remove is the correct reflection of how distance from the nucleus influences ionization energy.