Chemistry - PERIODIC TABLE Question with Solution | TestHub

(A) N < O (First ionization energy)

Incorrect because nitrogen has a stable half-filled $2p^3$ configuration.

Correct order: $N>O$

(B) Cl > F (Electronegativity)

Incorrect because electronegativity decreases down the group:

$F>Cl$

(C) H₂O < HF (Number of lone pairs)

H₂O: 2 lone pairs on O

HF: 3 lone pairs on F

Hence correct: $H_{2}O<HF$

(D) O > S (Electron affinity)

Incorrect because oxygen has a smaller size and more electron-electron repulsion.

Sulfur has higher electron affinity: $S>O$

Incorrect orders: A, B, D