Alkanes undergo free radical reactions due to strong C-C and C-H bonds

Steps:

• Recall alkanes are saturated hydrocarbons with only single bonds, making them unreactive to most addition or ionic mechanisms.
• Identify that alkanes react with halogens under UV light, involving homolytic bond cleavage.
• Recognize this as a substitution where a hydrogen is replaced by a halogen via radicals.
• Confirm free radical substitution as the primary reaction type for alkanes.

Why B is correct:

• Alkanes lack pi bonds or electron-rich sites, so they undergo free radical substitution (e.g., CH₄ + Cl₂ → CH₃Cl + HCl under UV), where radicals attack stable sigma bonds.

Why the others are wrong:

• A: Electrophilic addition targets pi bonds in alkenes, absent in saturated alkanes.
• C: Electrophilic substitution occurs in aromatic compounds like benzene, not alkanes.
• D: Nucleophilic addition involves electron-deficient centers in carbonyls, irrelevant to non-polar alkanes.

Final answer: B