JEE Main · 2026 · 23 Jan 2026 · Shift 2 · Classification of Elements and Periodicity

Across Group 15 the electronegativity drops sharply from nitrogen to phosphorus and then barely changes among the heavier members: N $(3.0)$, P $(2.1)$, As $(2.0)$, Sb $(1.9)$, Bi $(1.9)$. For $|{\chi }_X-{\chi }_P|$ to exceed $|{\chi }_P-{\chi }_Y|$, the large nitrogen--phosphorus gap must sit on the X side; taking X as nitrogen and Y as arsenic gives $0.9>0.1$, satisfying the condition. Hence X and Y are nitrogen and arsenic respectively.