Why is the fulminate ion unstable despite resonance stabilization?

[elliotyang]

Like the cyanate ion (NCO-), the fulminate ion (CNO-) has three resonance structures. Which is the most important contributor to the resonance hybrid? Suggest a reason fro the instability of fulminate.

 

[Bacat]

Please follow the template. This looks like the statement of the question you are trying to answer, but you haven't included relevant equations (or other information) and you haven't included your attempt at an answer.

Has your professor defined what resonance is? Are there different times? How has your class defined stability?