Reaction Time Science Presentation

On Wednesday we had a visit from a scientist at the Discovery Museum in Salt Lake.  She told us about the differences between physical changes and chemical reactions.  

She mixed Poly A and Poly B together and created foam!  It was definitely a chemical change since it had all 3 indicators: a change in state (liquid to solid), a change in color (dark brown to tan), and a change in energy (gave off heat).  She called him the Foam Gnome and offered it as a prize to the best class!