physical change because the observation of a solid forming is evidence of a state change, which is reversible
B
physical change because even though the mixture had a color that was different from either of the two solids alone, each solid’s physical properties remained exactly the same
C
chemical change because two substances were mixed, which always results in the formation of a new substance
D
chemical change because both a color change and a solid formation were observed, which provide strong evidence of a new substance