A student mixes two clear liquids together. After a few minutes, a white powdery solid can be seen settling on the bottom of the
test tube. Which of the following is a conclusion that the student can draw based on these observations? A:The two liquids are toxic and should be handled with extreme caution.
B:The two liquids were pure substances before they were mixed.
C:The two liquids have been stored too long and are no longer good.
D:The two liquids have gone through a chemical change in which a new substance called a precipitate was produced.
