Answer:
n = 5
Step-by-step explanation:
methane => 1 Carbon => CH₃
ethane => 2 Carbons => C₂H₆
propane => 3 Carbons => C₃H₈
butane => 4 Carbons => C₄H₁₀
pentane => 5 Carbons => C₅H₁₂
hexane => 6 Carbons => C₆H₁₄
heptane => 7 Carbons => C₇H₁₆ => CH₃(CH₂)₅CH₃
Octante => 8 Carbons => C₈H₁₈
Nonane => 9 Carbons => C₉H₂₀
Decane => 10 Carbons => C₁₀H₂₂