分子式
CH4 C2H6 C3H8 C4H10 C5H12
结构简式
CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3/CH(CH3)3 CH3CH2CH2CH2CH3/C(CH3)4/CH3CH(CH3)CH2CH3
别的不好打 你自己能写出来