Chemistry

Question Analysis
This question tests the student's understanding of the factors that influence atomic radius, specifically the role of nuclear charge and electron configuration.

Key Concept Explanation
The atomic radius is influenced by the balance between nuclear charge and electron shielding. Sodium (Na) and magnesium (Mg) are in the same period, but sodium has a lower nuclear charge (fewer protons), which results in a larger atomic radius.

Step-by-step Solution
1. Identify the elements given: Sodium (Na) and Magnesium (Mg).
2. Recall the factors affecting atomic radius: Nuclear charge and electron shielding.
3. Compare the nuclear charges: Sodium (11 protons) has a lo...