What is the formula for sodium nitride?

##"Na"_3"N"##

Sodium is an element in group 1 of . As such, it will form an electron by losing a single electron to form a ##"1+"## ion: ##"Na"^+##.

Nitrogen is an element in group 5 of the periodic table. When it forms the nitride ion, it gains three electrons to form a ##"3-"## ion: ##"N"^(3-)##.

In , the charges of constituent ions must balance. This can be achieved by having three sodium ions per nitride ion. Therefore, the formula of sodium nitride is ##"Na"_3"N"##.

However, ##"Na"_3"N"## is extremely unstable. It rapidly decomposes into its constituent according to the equation:

##2"Na"_3"N" -> 6"Na" + "N"_2##

It lacks a boiling point because of this. Since ionic have very high melting and boiling points as a result of the strong electrostatic attraction between oppositely charged ions that holds them together, sodium nitride should be no different; however, it will decompose as shown at around ##360## Kelvin (##"K"##) or ##86.85## ##""^@ "C"##.