HEL 6. A student performs an experiment and the results are shown below.
Before: Iron filings are brown, small, and magnetic; copper sulfate crystals are blue,
brittle, and not magnetic.
After: The copper formed was reddish, solid, and not magnetic; iron sulfide solution
was colorless and not magnetic.
Which statement supports that a chemical reaction took place?
A. Changes in color occurred.
B. A new substance was formed.
C. A physical change in the iron occurred.
D. The original substances were present after.