when the unbalanced equation of the formation of CuO is:
Cu + O2 → CuO
now the number of O atoms are not equal on both sides of the equation.
as O atoms on the left side 2 atoms and on the right side 1 atom.
so we will put 2 CuO instead of CuO
now the number of O atoms on both sides are equal 2
but now the number of Cu atoms are not equal on both sides so, we put 2 Cu instead of Cu.
∴ the final balanced equation of CuO formation is:
2Cu + O2 → 2CuO
