19. Which of the following should exhibit resonance? HCN CF4 BH3 SO2 H2CO 19. Which of the following should exhibit resonance? HCN CF4 BH3 SO2 H2CO HCN CF4 BH3 SO2 H2CO Solution Ans : SO2 SO2 exhibits two resonance structures . Both of these structures are equivalent to each other and contribute equally to the hybrid structure of the compound SO2. In both the structures , the negative formal charge is present on the more electronegative atom. .