Why is my answer wrong?

[jajaamanda]

My teacher asked to select the balanced equation describing the reaction between calcium and nitrogen.

I chose Ca(s)+N₂(g) --> CaN₂(s)

But the answer key says it should be

3Ca(s)+N₂(g) --> Ca₃N₂(s) because "Ca will form a +2ion and N will form a -3 ion. Nitrogen is diatomic." (her comment)

But...My equation is also balanced, is it not?

I checked it on an equation balancer at this site, and it comes back with my equation, so I'm not sure what the difference is.

Hoping for some clarity, thanks.

Amanda

[ChenBeier]

Yours is also balanced on paper, but your compound is not existing, that is the problem. Nitrogen has -3, two of them -6 .Calcium is +2. So how many Calcium you need?