Question

The correct order of metallic radius of the elements is

• A. $Be<B<Al<Mg<Li$
• B. $Mg<Li<Al<B<Be$
• C. $Li<Mg<B<Be<Al$
• D. $B<Be<Al<Li<Mg$
• E. $Li<Mg<Be<B<Al$

Hint:

Radius decreases left to right in a period and increases from top to bottom in a group.

Answer 1

The Correct Option is D

Concept: Chemistry - Atomic / Metallic Radius Trends.
Step 1: Across a period radius decreases. In Period 2: [ Li>Be>B ]
Step 2: Down a group radius increases. Since $Mg$ is below $Be$ and $Al$ is below $B$: [ Mg>Be,\quad Al>B ]
Step 3: Arrange from smallest to largest. Smallest is $B$, then $Be$, then $Al$, then $Li$, then $Mg$. [ \boxed{B<Be<Al<Li<Mg} ]
Step 4: Final answer.
Hence, correct option is (D).