What we learned in class:
A chemical change is when a compound changes its composition and a new substance is formed which has different properties. Some clues are bubbling or fizzing when a gas is formed, a cloudy substance when a solid is formed (a precipitate), a color change or a temperature change.

 Also, since new substances are formed from the atoms of the old substances, the mass will be the same.  No atoms are lost or created in the making of the reaction. They are just rearranged. This is a law of science -- the Law of the Conservation of Matter.

 ==Homework:
1. Answer the questions from the lab handout. (Many of the answers can be found on the cover page.)
2. Watch this video from The World of ChemistryThe World of Chemistry - Color 28 min. No notes required.
  [Click the VOD button for lesson 2, Color, and then click it again.   It works on the second try.]

Test on Chapter 17 next Thursday.  Come on Monday with your questions.
Levitating Pumpkins! Halloween Science  2 minute video.