Write a lewis structure for the co2−3 ion. how many equivalent resonance structures can be drawn?

To draw a lewis structure of CO2 -3, draw a circle at the center. Then draw two other circles below it with a good amount of distance between them. Next, connect the first circle to the other two circles. Show their valance electrons using dots around the element.  

The correct name for n3-ion should be azide.

The mass has escaped into a gas which you can not see so the law stays true.