CH2=CHCl\mathrm{CH}_{2}=\mathrm{CHCl}CH2=CHCl
CHCl3\mathrm{CHCl}_{3}CHCl3
H2O\mathrm{H}_{2} \mathrm{O}H2O
CH3COOH\mathrm{CH}_{3} \mathrm{COOH}CH3COOH
NH3\mathrm{NH}_{3}NH3