Well if the change is reversible then it is a physical change, but if not then it is a chemical change.
A decomposition reaction should look like
A ------> B +C+...
It has to have only one reactant and several products.
2 NO2 ⟶ 2 O2 + N2
<span>The solute is the substance that is being dissolved while the solvent is the base that the solute is bring dissolved in. For example, in salt water, salt would be the solute that dissolves into the water, and the water is the solvent that the salt is being dissolved in.</span>
I'm going on a limb here, but Carbon is a definite. <span />