contestada

Which, if any, of the substances had resonance structures? how many resonance did each substance have?
ccl4
h2o
co2
h2o2
ch4
c2h4
ch2o
ch3oh
ch3nh2
nf3
nh3
[nh4]
[no2]-
so2
of2
h2s
sf6
icl5