The outermost valence electron in atom A experiences an...

The outermost valence electron in atom A experiences an effective nuclear charge of $2+$ and is on average $225 \mathrm{pm}$ from the nucleus. The outermost valence electron in atom B experiences an effective nuclear charge of $1+$ and is on average $175 \mathrm{pm}$ from the nucleus. Which atom (A or B) has the higher first ionization energy? Explain.

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Shielding

Shielding refers to the phenomenon where inner electrons partially block the nuclear charge from being felt by outer electrons. This reduces the effective nuclear charge experienced by the outer electrons, thereby affecting the ionization energy.

Ionization Energy

Ionization energy is the energy required to remove an electron from an isolated gaseous atom. It depends on both the effective nuclear charge and the atomic radius; a higher effective nuclear charge and a smaller atomic radius generally lead to a higher ionization energy.

Atomic Radius

The atomic radius is the average distance between the nucleus and the outermost electrons. Electrons further from the nucleus experience a weaker attraction, making them easier to remove, while electrons closer to the nucleus are held more tightly.

Effective Nuclear Charge

This is the net positive charge experienced by an electron in an atom after accounting for the repulsion (shielding) effects from other electrons. A higher effective nuclear charge means that the electron is pulled more strongly toward the nucleus, making it harder to remove.

Transcript

Please give Ace some feedback