What does it mean when they say materials with the same properties but with different chemical composition? Can you give examples so that I can fully understand?
CuO and CuCl2 are solids but different composition.
Water, H2O, and ethanol, C2H5OH are different compounds but they are liquids, boil at 100 C or below, dissolve many of the same things, don't dissolve many of the same things, etc.