Question

The correct electronegativity order among Al, Ga, In, and Tl with respect to Pauling scale is:

• A. Al > Ga > In > Tl
• B. Tl > In > Ga > Al
• C. In > Tl > Ga > Al
• D. Al > Tl > In > Ga

Hint:

Remember: electronegativity decreases down a group and increases across a period.

Answer 1

The Correct Option is B

Step 1: Electronegativity trend down a group.
Electronegativity typically diminishes descending a group owing to increasing atomic radius and shielding. Thallium (Tl), the heaviest in group 13, has the lowest value, while aluminum has the highest.

Step 2: Pauling scale values.
Al = 1.61, Ga = 1.81, In = 1.78, Tl = 1.62.

Step 3: Correct decreasing sequence.
The observed order is Tl>In>Ga>Al.

Step 4: Final statement.
Therefore, option (2) is correct.