Which is the correct arrow pushing formalism to convert between the following resonance contributors?

Which of the following statements about the resonance structures of the formate ion (${\mathrm{HCO}}_{-}$) is correct?

Which of the following correctly represents a valid resonance structure for the cyanate ion $C_N{-}^1$ ($\mathrm{CNO}-$)?

For each pair of ions, determine which ion is more stable. Use resonance forms to explain your answers.

(e)

(f)

In the following sets of resonance forms, label the major and minor contributors and state which structures would be of equal energy. Add any missing important resonance forms.

(d)

(e)

Use resonance structures to identify the areas of high and low electron density in the following compounds:

(a)

(b)

(c)