MCQ
Which of the following undergoes substitution reaction?
- A$\ce{Ethylene + HCl ->}$
- B$\ce{Ethyl chloride ->[Alcoholic NaOH][\Delta]}$
- ✓$\ce{Methane + Cl2 ->[UV light]}$
- D$\ce{Isobutyl alcohol ⇌[H^+]}$
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α-helix structure : Keratin :: β-pleated sheet : ____________.