CH3Cl\mathrm{CH}_{3} \mathrm{Cl}CH3Cl
CH3Br\mathrm{CH}_{3} \mathrm{Br}CH3Br
CH3 F\mathrm{CH}_{3} \mathrm{~F}CH3 F
CH3I\mathrm{CH}_{3} \mathrm{I}CH3I