Question

multiple choice 1 point
group -1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
period
periodic table image
which selection has an order of elements from largest atomic radius to smallest?
○ na, pb, p, cs
○ cs, na, pb, p
○ p, na, pb, cs
○ cs, p, pb, na

Explanation:

Step1: Recall atomic radius trends

Atomic radius increases down a group (more electron shells) and decreases across a period (increased nuclear charge).

Step2: Analyze each element's position

• Cs: Group 1, Period 6 (many shells, large radius).
• Na: Group 1, Period 3 (fewer shells than Cs, smaller than Cs).
• Pb: Group 14, Period 6 (same period as Cs, but right in period, smaller than Cs; more shells than Na, larger than Na).
• P: Group 15, Period 3 (same period as Na, right in period, smaller than Na).

Step3: Order from largest to smallest

Using trends: Cs (largest) > Na > Pb > P. Check options: only "Cs, Na, Pb, P" matches.

Answer:

B. Cs, Na, Pb, P (assuming the second option is this; if options are labeled, use the correct label with text)