Chemistry

Question Analysis
This question evaluates the understanding of the trend in atomic radius across a period and the underlying reasons for this trend.

Key Concept Explanation
The atomic radius is influenced by the balance between the attractive force of the nucleus (nuclear charge) and the repulsive force of the inner electrons (electron shielding). As you move from left to right across a period, the number of protons increases, leading to a stronger attraction of the valence electrons to the nucleus.

Step-by-step Solution
1. Identify the trend: Atomic radius decreases from left to right across a period.
2. Understand the reason: Increasing nuclear charge (more protons) pulls valence electrons closer to the nucleus.
3. Note that electron shielding remains c...