What is the BIG idea
• Matter has properties that can be changed by Physical and chemical processes.
Physical Properties
• Characteristics you can observe without changing the identity of the substance
Color
Shape
Size
*Examples of Physical properties*
• Mass and Volume• Thermal Conductivity• State• Density• Solubility• Ductility• Malleability
Thermal Conductivity:
• The rate at which a substance transfers heat
Strong conductor Poor
conductor
State
• The physical form in which a substance exists. Such as a solid, liquid, or gas.
Ice is water in a solid state.
Malleability
• The ability of a substance to be rolled or pounded into thin sheets
• Example Sulfar and Gold
Density
• The measure of how light or heavy something is for its size.
• Density is measured by dividing an object’s mass by its volume.
Which ball takes up more space? Which ball has the most mass? Which of these ball do you think is the most densest?
Density and Liquids
• Liquids have different densities• Liquids that are least dense will float
To the top.• Liquids that are most dense will sink
To the bottom.• Water’s density is 1.• Find a liquid with a density greater • Than Dawn Dish Soap.• Find a liquid with a density less than water
Density and Solids
• Which would you carry all day?• A bag full of Tomatoes or a Bag full of
Cotton balls
Guess What!
• The cotton balls and Tomatoes actually have the same mass!
• *WHAT!!! • Remember , because mass is
the amount of matter.• Matter is the amount of space an
object takes up.
BUT….
• Cotton is much less dense than the tomatoes.
• Remember density the amount of matter in a given space.
The purple circles represent how much space that is available (volume) the black stars represent the amount of matter in that space.
Guess What?
• Knowing the density of a substance can tell you if the substance will float or sink in water!
Solving for Density
• To find the objects Density (D)• Measure the Mass (m) and
Volume (V)• D= m/V• The units for a solid may be
g/cm3 and kg/m3.
Calculating Density
• A glass marble has a volume of 5cm3, mass of 13g. What is the density of the glass?
Always Follow these steps when solving for density
• What do you know? V= 5cm3 and M=13g
• What do you need to know? Density
• What formula are you using? D=m/v
D * V
M
The hard part is done!
• Substitute numbers into formula
D=13g/ 5cm3
• Calculate and Simplify: D= 2.6g/cm3
How to use the formula Triangle
• Cover your finger over the letter you are looking for.
• If finger covers D that means m/v• If finger covers M that means D*V• If finger covers V that means m/D
Tip for your kitchen
• The density of an egg decreases as it ages because as it spoils it loses water. If the egg floats it may be spoiled!!
Physical Changes• A physical change changes one or more
physical properties.
• PHYSICAL CHANGES DO NOT CHANGE THE SUBSTANCE
• Too break it down to you better, if an object goes through a physical change the object’s identity doesn’t change!
Physical change Example
Gold NecklacePiece of Gold
What Changed? The shape of the substanceWhat didn’t Change? The fact that it is still gold
Taking it old school…
• Do you remember Weathering from Earth Science?
• Physical Weathering Breaking down Rocks
• Did the identity change?• What changed?
More examples of Physical changes
• Crushing a can• Breaking a Pencil• Melting Butter• Dissolving Sugar in Water• Erosion
• Add three examples on your own paper. Be prepared to share.
What does physical properties and change have in common?• A physical change such as slicing
An apple changes the shape of
The apple but NOT the identify of
The apple .
Let’s Review ( Input this information on Edmodo)
• What physical properties do the following have in common?
• Which physical properties are different?
• A glass marble has a volume of 5cm3 and a mass of 13g. What is the density?
• How are physical properties and physical changes related?
Stop Here Please
You should have written your notes on the cornell notes side (left)
Place your review questions on EdmodoInclude any confusions you may have
had from these notesDo not do the right side reflection side
just yet.
Standards
• S8P1.d: distinguish between physical and chemical properties of matter as physical or chemical.
• S8P1.e distinguish between changes in matter as physical or chemical.
Example 2
•ReactivityThe ability of 2 or
more substances combined and form one or more substances
• Iron + Oxygen = Rust
• Iron from an old car reacts with oxygen will cause car to rust.
Example 3
• Antacid tablet dropped into a glass of water.
• As the tablet dissolves bubbles appear this is carbon dioxide forming bubbles.
Chemical Change
• When one or more substances are changed into new substances that are new and have different properties
Chemical Changes Can be Yummy!
After you bake the batter you come up with something totally different.
*YUMMY ( Mrs. Johnson Wedding Cake)
• The heat and the interaction of the ingredients cause a chemical change that is yummy!
• The result is a cake and the properties between the batter and the cake changed!
Signs of Chemical Change
• Soured Milk: bacteria in milk has formed causing the milk to chemically change.
• Change in color: when a fruit ripens• Change in odor: sour milk• Fizzing and foaming: POPROCKS IN
COKE • Change in temperature:
Comparing Physical and Chemical PROPERTIES
Physical Change
• You can observe physical properties.
• Example: changing the shape of wood
Chemical Change
• It is hard to observe unless it is actually happening.
• Example: You can see if wood is flammable by burning it.
Difference between Chemical Change and properties
Chemical Change
• Occurs when one or more substances are changed to something new!
Chemical Properties
• Determines whether a chemical change will happen
Physical Change vs Chemical change
Physical• Physical change doesn’t
change the composition.• Wood cut in half is still
wood!• You can reverse a
physical change. ( ice melted in water, but you can refreeze the water and turn it back to ice)
Chemical• Chemical Change alters
the substance.• Wood burned turns to
ashes ( something totally different)
• Very difficult to reverse a chemical change. You can’t unbake a cake back to the original ingredients.
Things to Do after completing your cornell notes
Check out the video Check out the video and see if you can
guess if the changes were physical or chemical http://www.bcscience.com/bc9/pgs/videos_012_chemchange.html
Check out this youtube video ( we will learn this song) except the lame dancing) http://www.youtube.com/watch?v=VnbTQupMjO8
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