Chemistry

Question Analysis
This question evaluates the understanding of periodic trends, specifically the trend in atomic radius across a period.

Key Concept Explanation
As you move from left to right across a period, the atomic radius generally decreases due to the increasing nuclear charge, which pulls the valence electrons closer to the nucleus.

Step-by-step Solution
1. Identify the elements in Period 5: Rubidium (Rb), Strontium (Sr), Yttrium (Y), and Zirconium (Zr).
2. Compare their positions in the periodic table:
Rb is in Group 1 (alkali metals).
Sr is in Group 2 (alkaline earth metals).
Y is in Group 3 (transition metals).
Zr is in Group 4 (transiti...