A radical contains ${ }^{14} \mathrm{N}(\mathrm{I}=1)$ with hyperfine constant 1.61 mT and two equivalent protons $(\mathrm{I}=1 / 2)$ with hyperfine constant 0.35 mT . The ESR spectrum will exhibit.
(a)3 lines
(b)6 lines
(c)7 lines
(d)9 lines
Answer
Answer: D ✓ checked by 4AB · confidence high
Explanation
One ¹⁴N (I = 1) gives 3 lines, each split into 3 by two equivalent protons: 3 × 3 = 9 (d).