Question

Mendeleev and Moseley have taught you that elements are grouped together based on their valence electron configurations.
How does this affect ionization energy going down the group?

• A. Ionization energy increases down the group as the number of electron orbitals increases.
• B. Ionization energy increases down the group as the number of electron orbitals decreases.
• C. Ionization energy decreases down the group as the number of electron orbitals increases.
• D. Ionization energy decreases down the group as the number of electron orbitals decreases.

Answer 1

The correct option is B Ionization energy increases down the group as the number of electron orbitals decreases.

The ionization energy increases down the group, as the atomic size increases. The size increases as the number of orbitals increase. Thus the IE decreases down the group as number of orbitals increases. Option B