Radical Intermediates in Chlorination of Ethane Steps:

• Chlorine radicals form via homolytic cleavage of Cl₂.
• A chlorine radical abstracts a hydrogen from ethane (CH₃CH₃), forming HCl and an ethyl radical (CH₃CH₂•).
• The ethyl radical reacts with Cl₂ to form chloroethane (CH₃CH₂Cl) and regenerate Cl•.
• Termination steps involve radical combinations, but propagation generates the key alkyl radical.

Why B is correct:

• CH₃CH₂• is the alkyl radical produced when Cl• abstracts H from ethane, per the propagation step in free radical substitution.

Why the others are wrong:

• A: CH₃• forms from methane (CH₄), not ethane.
• C: CH₃Cl• is a radical from chloromethane, unrelated to ethane chlorination.
• D: CH₃CHCl• arises in secondary chlorination of chloroethane, not the primary reaction with ethane.

Final answer: B