Question

1pt atomic radius tends to decrease as you move _________.

○ a. up a column on the periodic table

○ b. down a column on the periodic table

○ c. from right to left across the periodic table

○ d. from the top - right to the bottom - left of the periodic table

Explanation:

• Option A: As you move up a column (group) in the periodic table, the number of electron shells decreases. Since the outermost electrons are closer to the nucleus, the atomic radius decreases.
• Option B: Moving down a column, the number of electron shells increases. This causes the outermost electrons to be farther from the nucleus, increasing the atomic radius.
• Option C: Moving from right to left across a period, the effective nuclear charge decreases (because the number of protons increases less than the shielding effect in this incorrect direction). But actually, atomic radius increases from right to left across a period.
• Option D: From top - right to bottom - left, considering both group and period trends, the atomic radius generally increases.

Answer:

A. up a column on the periodic table