Q.11 The CORRECT order of electronegativity is
(A) Al > Si > P > S
(B) Al > S > Si > P
(C) S > Si > Al > P
(D) S > P > Si > Al

The correct answer is (D) S > P > Si > Al.

Pauling electronegativity values confirm this decreasing order for these Period 3 elements.

Electronegativity Values

Standard Pauling scale values are: S (2.58), P (2.19), Si (1.90), and Al (1.61). Electronegativity increases across Period 3 from left to right due to rising effective nuclear charge and shrinking atomic radius, which strengthens electron attraction in bonds.

Option Analysis

• (A) Al > Si > P > S: Incorrect, as values show Al (1.61) < Si (1.90) < P (2.19) < S (2.58), reversing the period trend.

• (B) Al > S > Si > P: Incorrect; Al is lowest (1.61), while S (2.58) exceeds both Si and P.

• (C) S > Si > Al > P: Incorrect; Si (1.90) < P (2.19), so P exceeds Si despite Al’s lower value.

• (D) S > P > Si > Al: Correct, matching 2.58 > 2.19 > 1.90 > 1.61 exactly.

Electronegativity measures an atom’s ability to attract bonding electrons, crucial for CSIR NET Life Sciences and Chemistry exams focusing on order of electronegativity Al Si P S. In Period 3, this property rises from metals to nonmetals due to increasing nuclear charge pulling electrons closer.

Pauling Scale Basics

Linus Pauling’s scale assigns fluorine 3.98 (near 4.0); Period 3 values follow: Al 1.61, Si 1.90, P 2.19, S 2.58. This confirms S > P > Si > Al as the decreasing order.

Why Option D Wins

All sources align on these values, eliminating other sequences. For competitive exams, memorize the trend: metals (low) to nonmetals (high).