Introduction
Chemical changes are changes in which a substance is changed into a different substance. Chemical changes occur when a chemical reaction causes bonds between atoms to break or to form. (Some in completely new forms.) Evidence that a chemical change has occured might include: a color change (not always the best evidence), an odor change, formation of a precipitate (you mix two liquids and make a solid), gas is formed (bubbles), changes in physical properties. During a chemical change, energy can be released in the form of: heat and light. When a chemical change occurs, energy is either released or absorbed. Exothermic is when heat is released. Endothermic is when goes in a substance.
Task
Process
Now that you have watched the videos and read the article, do the following:
1. Read the article.
2. Click "Examples of Physical Changes and Chemical Changes" and read.
3. Click "10 Chemical Change Examples" and read.
4. Watch the two videos and copy notes.
Conclusion
By now, you should better understand chemical changes. I hope your knowledge has improved because there could possibly be a pop quiz on chemical changes and you will know a whole bunch of information and ace the test.