Balance the chemical equation. (blank) n2o3 → (blank) n2 + (black) o2

  The balanced equation is as below

 2 N₂O₃ →  2N₂ + 3O₂

Explanation

According  to the law  of mass conservation the  number of atoms  in reactants side must  be equal  the to the number of atoms in products  side.

 Therefore the  balanced reaction  above is balanced  since the number of atoms  in reactants side  are equal to number of atoms in products side.

For  there 4 atoms  of N   in reactants  side and  4 in products side.

The balanced equation is  2 N₂O₃ →  2N₂ + 3O₂

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.