The N3 ion is generally known as azide, trinitrogen ion or hydrazoate. N3 is formed by joining three nitrogen ions together, which results in the center atom having a positive charge and the atoms on either side being negatively charged.
In this formation, each of the two negatively charged ions give up one of their electrons to form a positively charged atom in between the two.
Azide has an atomic mass of 42.0201 grams per mole. This ion has very few practical or industrial applications, although it is commonly used in the automotive industry as a propellant for air bags.