GCEChemistryAtomic Structure and Periodicity2023

The atomic radius generally decreases across a period from left to right because

Athe number of neutrons in the nucleus increases
Bthe nuclear charge increases while electrons are added to the same shellCORRECT
Cthe number of electron shells increases progressively
Dthe shielding effect increases significantly across the period
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Why the answer is B, and why the others tempt you.
Across a period, the atomic number (nuclear charge) increases but electrons are added to the same principal energy level. The increased nuclear charge pulls the electron cloud closer to the nucleus without a significant increase in shielding, resulting in a smaller atomic radius. The number of shells does not increase within the same period.
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