# Problem: The shielding of electrons gives rise to an effective nuclear charge, Zeff , which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively?A) +5 and +8B) +3 and +6C) +5 and +6D) +3 and +8E) +1 and +4The atomic radius of an element can be predicted based on its periodic properties. Atomic radii increase going down a group in the periodic table, because successively larger valence-shell orbitals are occupied by electrons. Atomic radii generally decrease moving from left to right across a period because the effective nuclear charge increases.

###### Problem Details

The shielding of electrons gives rise to an effective nuclear charge, Zeff , which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively?

A) +5 and +8
B) +3 and +6
C) +5 and +6
D) +3 and +8
E) +1 and +4

The atomic radius of an element can be predicted based on its periodic properties. Atomic radii increase going down a group in the periodic table, because successively larger valence-shell orbitals are occupied by electrons. Atomic radii generally decrease moving from left to right across a period because the effective nuclear charge increases.

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