Question

question 9. which of the following elements have a smaller atomic radius than phosphorus (p)? select all that apply.
□ sulfur (s)
□ chlorine (cl)
□ silicon (si)
□ oxygen (o)
□ sodium (na)
□ nitrogen (n)

Explanation:

Step1: Recall atomic radius trends

Atomic radius decreases across a period (left to right) and increases down a group (top to bottom) in the periodic table. Phosphorus (P) is in period 3, group 15.

Step2: Analyze each element

• Sulfur (S): Period 3, group 16. Across period 3, from P (group 15) to S (group 16), atomic radius decreases (more protons, same energy level, stronger attraction). So S < P.
• Chlorine (Cl): Period 3, group 17. Further right in period 3 than P, so radius decreases: Cl < P.
• Silicon (Si): Period 3, group 14. Left of P in period 3, so radius increases: Si > P.
• Oxygen (O): Period 2, group 16. Up a group from P (period 3 to 2) and right in group (15 to 16). Both trends (up group: smaller; right in period: smaller) make O < P.
• Sodium (Na): Period 3, group 1. Left of P in period 3, radius increases: Na > P.
• Nitrogen (N): Period 2, group 15. Up a group from P (period 3 to 2), so radius decreases: N < P.

Step3: Identify elements with smaller radius

Sulfur (S), Chlorine (Cl), Oxygen (O), Nitrogen (N) have smaller atomic radii than P. Silicon (Si) and Sodium (Na) have larger.

Answer:

A. Sulfur (S), B. Chlorine (Cl), D. Oxygen (O), F. Nitrogen (N)