1. Page 23 Chemistry unit learning goal
October 25, Day 2
1. Please have these
Items on your desk.
Science Starters
Sheet
notebook
Agenda
Science Starter:
Page Chemistry unit learning goal
Choose 3 assignments to score and graph

2. The look of Science Fair
Wednesday-Data Chart & Graph due

3.
Bozeman video clip

4. Evidence of Chemical Reactions
Chemical Reaction: The process by which the atoms of one or more substances are rearranged to form different substances.
Temperature change
Color change
Gas or solid appears

5. 4. An energy change (Temperature)
Endothermic reaction-a chemical reaction accompanied by the absorption of heat.
Exothermic reaction-a chemical reaction that releases energy. The energy “ex”its. It is the opposite of an endothermic reaction.

6. Example of everyday endothermic reactions

7. Examples of everyday exothermic reactions

8. Law of Conservation of Matter
Matter is conserved  type of atoms does not change
Nothing is created or destroyed

9. Change of Matter::::Physical change: Identity Retained.

This type involves a change in the observable properties of matter without a change of the substance identity.  In most physical change of matter, no bonds are broken between atoms and the identity of the substance is retained.
Example:  Phase Change  
In a phase change matter changes from solid, liquid or solid but the identity of the substance is retained. 
 

10. Change of Matter:::::Chemical change: Identity Changed

This type of change refers to a material changing to a completely different type of material or transformation to a new substance. This process involves bond breaking and bond forming such that material changes identity. 
 
Example:  Decomposition of water.
In the decomposition of water, water molecules H2O are broken down to hydrogen and oxygen.

11. Consider the following examples, which of these are phyiscal and which are chemical change
Heating sugar vs. adding sugar to water
Cutting wood vs. burning wood.
3. The electrolysis of water vs. ice melting.

12. Answers. . . . . . . .. Physical Change Chemical Change
1. Sugar dissolving Sugar heating
2. Cutting Wood Burning Wood
3. Melting Ice Electrolysis of water