Question

The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is:

• A. \( \text{A}_2\text{O}_3 \)
• B. \( \text{AO}_2 \)
• C. \( \text{A}_2\text{O} \)
• D. \( \text{A}_2\text{O}_4 \)

Hint:

The atomic radius decreases across a period from left to right due to an increase in nuclear charge, which pulls the electrons closer to the nucleus.

Answer 1

The Correct Option is A

Nuclear charge increases from left to right across a period, causing a general decrease in atomic radius. For the elements Li, Na, Be, Mg, B, and Al, atomic radius diminishes from Li to Al. Aluminum (Al), which forms \( \text{A}_2\text{O}_3 \), has the least atomic radius among these elements.
Therefore, the correct answer is \( \boxed{(1)} \).