Properties Help Distinguish Different Materials Practice Test

Three white powders looked identical, so color didn’t help. All three dissolved in water, so dissolving didn’t help either. Only one powder fizzed when vinegar was added. Which property was most helpful for distinguishing the powders?​

Two materials were both brown and smooth, so those properties did not help. One was magnetic, very heavy for its size, and sank; the other was not magnetic, light for its size, and floated. Explain why different properties are needed to distinguish materials here.