Question

Why magnesium ribbon dipped in jar of nitrogen not magnesium rod?

Answer 1

When magnesium is burned in air some of themagnesium also reacts with nitrogen in the air and some magnesium nitride is also formed. ... At normal temp nothing, but Mg reacts with N2 and MgO will decompose at some temp so if they are mixed with excess N2 at some high temp and cooled some Mg3N2 will be formed.