Answer:
burning a paper is chemical change
wave length is what he decreased
The solute is the part of the solution that dissolves in the second component (usually a fluid). Therefore, for the mentioned solution, the solute is ehyl alcohol since it is the one dissolving in water.
As for the solvent, it is the component in which the solute dissolves. In this case, it is water.
A iron combines with oxygen to produce rust, which is the compound named iron