1. Bell Ringer
Write all that you know about the following objects (Describe them in detail.):
Strawberry
Sunshine
Metal
Wood

2. ALCOS Objectives:
#1- Identify the steps of the scientific method
#4 State the law of conservation of matter (Balancing Chemical Equations)

3. Chapter 6 Section 1
Chemical Reactions

4. Matter Matter can be described in terms of two kinds of properties.
Changes in matter can be described in terms of physical changes and chemical changes.

5. Physical property Ability to change appearance
It is a characteristic of a substance that can be observed without changing the substance into another substance.
Ex: melting point, boiling point, color, hardness, texture, solubility, buoyancy

6. Chemical property- ability to form a new substance
A chemical property is a characteristic of a substance that describes its ability to change into other substances.
Ex. flammability, tarnishing, combustion, rusting

7. Physical changes- changes how it looks
Any change that alters the form or appearance of a substance but that does not change it into something new.
Ex: bending, crushing, breaking, cutting

8. Chemical change- forms new substance
Chemical changes occur when bonds break and new bonds form. As a result, new substances are produced.
Raw egg to a cooked egg……
Bleaching or perming your hair

9. Bonding
Chemical changes occur when bonds break and new bonds form. = +

10. Geyser

11. Roasting Marshmallows

12. Evidence for chemical reactions:
A color change
A precipitate is formed (a solid that is formed from solution – pg. 188)
Bubbles or gas produced
A change of temperature

13. Examples of precipitates:

14. Physical Change or Chemical Change?

15. Changes in Energy
Endothermic Reactions- reaction in which energy is absorbed
Exothermic Reactions- reaction that releases energy in the form of heat

16. Examples
A piece of metal is heated to a high temperature and changes to a liquid.
When 2 solutions are poured into the same container, a powdery solid forms and settles to the bottom.
Water left in a dish overnight disappeared by the next day.
A blacksmith hammers a piece of red-hot iron into the shape of a knife blade.

17. Exothermic or Endothermic?
Oil is burned
An electric eel shocks its prey
A cake bakes
Someone strikes a match
A flashbulb flashes on a camera
Dead plant material decays producing warm compost
Fireworks explode
Clay turns to brick when it is heated in a kiln at high temperatures
Chemical reactions occur in a battery
A firefly flashes its light