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

1. B

2. 100 C

3.  C

4. D

5. D

Explanation:

i believe it is 40–40–20%

explanation:

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: