1. Physical & Chemical Changes
Changing Matter
Physical & Chemical Changes

2. What different ways can we differentiate between people?
Properties
How we identify something.
All substances have properties that we can use to identify them. For example we can identify a person by their face, their voice, height, finger prints, DNA etc.. The more of these properties that we can identify, the better we know the person. In a similar way matter has properties - and there are many of them. There are two basic types of properties that we can associate with matter.

3. Matter has properties
Two basic types of properties that we can associate with matter.
Physical properties
Chemical properties

4. Physical Properties
Anything that can be observed without changing the identity of the substance. (Tends to be measurable.)
melting point
density
boiling point
thermal conductivity
electrical conductivity
ductility
color
malleability

5. Malleability
The ability of an object to be molded into different shapes.
Example – metals.
Opposite – Brittle, not flexible.

6. Ductility
The ability of an object to be drawn into thin wires without losing strength.
Metals are ductile.

7. Combustion - the process of burning something
Chemical Properties
The way a substance may change or react to form other substances
combustion
Reactivity to other chemicals
reactivity with water PH
Oxidation
Flammability
Chemical properties of matter describes its "potential" to undergo some chemical change or reaction by virtue of its composition. What elements, electrons, and bonding are present to give the potential for chemical change.
It is quite difficult to define a chemical property without using the word "change". Eventually you should be able to look at the formula of a compound and state some chemical property. At this time this is very difficult to do and you are not expected to be able to do it.
For example hydrogen has the potential to ignite and explode given the right conditions. This is a chemical property.
Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property.
Combustion - the process of burning something

8. Matter can be changed two ways
Physically
Physical reaction
Physical change
Chemically
Chemical reaction
Chemical change

9. Physical Changes Do NOT CHANGE THE TYPE OF MATTER
Nothing new or different is formed
Could be a change in:
Mass
Volume
Density
Change in state
Color
Shape
Size

10. Physical Changes
Substance may seem different, but the way the atoms link up is the same.
It changes phase (freezes, boils, evaporates, condenses, sublimates)

11. Examples of Physical Changes
Boiling
Freezing
Dissolving
Breaking
Making a mixture
2 or more types of matter (substances) mixed together
Not in specific amounts
Can be separated physically

12. Chemical Changes
Chemical changes, or chemical reactions, are changes that result in the production of another substance. 
Changes the way the molecules link up (chemical composition)
Makes new substances (new compounds, or compounds are broken down into the elements that make them up)
The substances present at the beginning of the change are not present at the end; new substances are formed. The change cannot be “undone.”

13. Chemical Changes Evidence of a chemical reaction Formation of gas
Formation of precipitate
Change in color
Change in energy (temperature)
Endothermic Absorbs heat energy (gets cold)
Exothermic Releases heat energy (gets hot)
Alka-Seltzer: (Baking soda or sodium bicarbonate) NaHCO3 + Citric acid ---> CO2 + H2O + Sodium Citrate

14. Chemical Changes
Atoms are re-arranged, NOT created or destroyed

15. It’s a chemical change if….
It burns
Temperature changes without heating/cooling

16. It’s a chemical change if….
It bubbles (makes a gas)

17. It’s a chemical change if...
It changes color
It forms a precipitate – (solid that forms from two liquids).

18. Again signs that a Chemical Change has occurred
Creation of a gas (bubbles)
Creation or loss of heat
Fire
Rotting
Breaking down (decomposition)
Precipitation (Sour milk clumps)
Cooking
Rusting (oxidation)

19. Chemical Change
The only TRUE sign that a chemical change has taken place is the formation of a new substance.
A new substance that was not there before.
A new substance with a new chemical composition (Atoms are arranged differently).

20. Basically What You’re Telling Me Is…
If you end up with a chemical or chemicals that you did not start with,
It is a chemical change!!!!!!!

21. Another Example Is… Eating…
Now eating can change food both physically and chemically.
Chewing is Physical but…
Once the food touches the chemicals in the saliva begin to change the food chemically.

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

23. Law of Conservation of Mass
Mass is conserved  amount of atoms cannot change
Nothing is created or destroyed

24. What kind of change is it if someone...
Tears up paper?
Physical change
Mixes salt and water?

25. What kind of change is it if someone...
Burns paper?
Chemical change
Evaporates salt water?
Physical change

26. What kind of change is it if someone...
Mixes vinegar and baking soda?
Chemical change

27. Physical and Chemical Changes Quiz ……….True or False??
1. With a physical change, no new substance is formed.  
2. With a chemical change, a chemical reaction occurs.
3. With a physical change, energy is either given off or absorbed.
4. A chemical change can be easily reversed.
5. Eating food can be considered both physical and chemical changes.

28. Physical and Chemical Changes Quiz……….Answers!
1. With a physical change, no new substance is formed.  TRUE
2. With a chemical change, a chemical reaction occurs. TRUE
3. With a physical change, energy is either given off or absorbed. FALSE
4. A chemical change can be easily reversed. FALSE
5. Eating food can be considered both physical and chemical changes. TRUE

29. ONLINE QUIZ

30. Physical or Chemical Change?
Painting Wood
PHYSICAL

31. Physical or Chemical Change?
A ring tarnishing
CHEMICAL

32. Physical or Chemical Change?
Tarnish is a thin layer of corrosion that forms over copper, brass, silver, aluminum, magnesium and other similar metals as their outermost layer undergoes a chemical reaction. It causes to lose luster.

33. Physical or Chemical Change?
Burning Paper
CHEMICAL

34. Physical or Chemical Change?
Digestion of food
CHEMICAL

35. Sugar dissolving in water PHYSICAL
Physical or Chemical Change?
Sugar dissolving in water
PHYSICAL

36. Iron turning red when heated PHYSICAL
Physical or Chemical Change?
Iron turning red when heated
PHYSICAL

37. Physical or Chemical Change?
Evaporation
PHYSICAL

38. A pond freezing in winter PHYSICAL
Physical or Chemical Change?
A pond freezing in winter
PHYSICAL

39. Physical or Chemical Change?
Melting ice
PHYSICAL

40. Physical or Chemical Change?
Cutting wire
PHYSICAL

41. Physical or Chemical Change?
Painting fingernails
PHYSICAL

42. Physical or Chemical Change?
Cutting fabric
PHYSICAL

43. Physical or Chemical Change?
Baking muffins
CHEMICAL

44. Physical or Chemical Change?
Shattering glass
PHYSICAL

45. Decomposition of old leaves CHEMICAL
Physical or Chemical Change?
Decomposition of old leaves
CHEMICAL

46. Physical or Chemical Change?
Wrinkling a shirt
PHYSICAL

47. Physical or Chemical Change?
An old nail rusting
CHEMICAL