Successive alkanes differ by :

Step-by-step solution

Alkanes have a general formula C _n H _ 2 n+2 So, when aligned & n=1, C ₁ H _ 2 1+2 = CH ₄ & n=2, C ₂ H _ 2 2 +2= C ₂ H ₆ & n=3, C ₃ H _ 2 3+2 = C ₃ H ₈ aligned So, the all have a difference of CH ₂ .