Boron reacts with air to give

Boron& is a chemical element& with the symbol& $B$~and atomic number~$5$. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous~form it is a brown powder.

Air contains ${O}_{2}, {N}_{2}$ in max proportions
$4B + 3{O}_{2} \to 2{B}_{2}{O}_{3}2B + {N}_{2} \to 2BN$

Boron reacts with air to give the mixture of ${B}_{2}{O}_{3}andBN$.