What is the most obvious sign of a chemical change in this reaction.
a. a gas was produced.
b. the powder mixed with the water.
c. there was a change in temperature. eliminate
d. the powder dissolved in the water.?

Assignment directions: pick one of the following chemists and perform a bit of research on him/her. answer the following questions. alice hamilton             rosalind franklin marie curie             gertrude b. elion ada yonath             henry cavendish robert boyle             antoine lavoisier mario j. molina             svante arrhenius