A blue crystalline material is heated strongly in a test tube. A clear liquid condenses around the mouth of the tube and the crystals gradually lose their blue color and become white powder. Every gram of blue crystals produces 0.36 g of clear liquid and 0.64 g of colorless powder. The same weight relationships are observed for smaples of the crystals taken from many different sources. These observations are consistent with the hypothesis that the blue crystals are:
A.) a compound
B.) a heterogeneous mixture
C.) a solution
D.) an element
E.) a wet salt
