Which of the following is a pure substance?
Chlorine B. salt solution C. bronze D. salad dressing

What is the boiling point of pure water?
About 1000 C B. exactly 1000 C C. it varies D. slightly above 1000 C

Which is an example of a chemical change?
Water evaporating B. butter melting C. match burning D. powder being made

Which of these indicate a chemical change?
Color change B. temperature change C. gas-forming D. all of the above

Which of these is an impure substance?
Tap water B. gold C. carbon dioxide D. boron