Which combinations of substances resulted in a chemical change?

Any chemical reaction would always result to a chemical change. If you can see observations of a change in color, bubbling or any liberation of gas, formation of a precipitate, or a change in temperature, then a chemical change has occurred. I can't say which combinations would result to a chemical change because there are no choices. I can only give an example. If HCl reacts with NaOH,

HCl + NaOH → NaCl + H₂O

This is a chemical change because a precipitate in the form of NaCl salt is formed.