Chapter 8
Lesson 2
SPI’s:
Physical and Chemical Properties
Who remembers what matter is?
 Matter
is anything with mass (weight)
and takes up space.
 So
properties describes matter
 What
properties of wood and metal make
them better materials for a baseball bat
than paper or glass? (Remember,
properties describe matter…)
 Wood
and metal are stronger and less
breakable than paper or glass.
(Can you imagine a baseball bat made of
paper or glass?)
wood and metal = Matter
stronger and less breakable = Properties
glass and paper = Matter
 How
are the physical properties of paper
and aluminum foil alike and different?
 Compare
(Alike) Both are:
 Thin
 Flexible
 Flat
 Contrast
(Different)
 Paper is white and dull
 Foil is silver and shiny.
 How
do you know that a chemical change
takes place when paper burns?
 New
matter is produced that has a
different identity (look or appearance)
and different properties from the original
paper.
Physical and Chemical properties!!!
Let’s continue by reading
PP. 298 and 299
How are the physical properties of solids
and liquids alike and different?
Compare: (Alike)
Both have definite volume
Contrast: (Different)
Solids have a definite shape
Liquids take on the shape of their container
What if you have two samples of an unknown
substance that have the same color, texture,
and density. How could you use temperature
changes to find out if they are the same
substance or different substances?
(Refer back to the selection if necessary)
Find the samples’ melting and/or boiling
points. If the samples have the same
melting point and the same boiling point,
they are probably the same substance.
Ahhh, now you’re catching on…
A mixture of water and rubbing alcohol is
heated. At 82 degrees Celsius, the mixture
begins to boil, and some of the liquid turns
into gas. The rest of the liquid doesn’t turn to
a gas until the temperature is increased to
100 degrees Celsius. What is happening to
the mixture as it is heated?
Hint: Remember, this is a mixture.
Rubbing alcohol’s boiling point is 82
degrees Celsius, while water’s boiling point
is 100 degrees Celsius. When you heat the
mixture, it first reaches rubbing alcohol’s
boiling point, and the rubbing alcohol
begins to turn into a gas. When it reaches
water’s boiling point, the water begins to
turn into a gas.
Solubility and Conductivity PP. 300 and 301
What new material is formed when
wood is burned?
Burnt wood turns to ash.
A metal bicycle that begins to rust after
being left out in the rain has undergone what
type of change, physical or chemical? How
do you know?
Chemical, because the rust is a different
kind of matter than metal.
What type of change is caused by cutting?
Physical or chemical? Explain.
What kind of change is caused by burning?
Physical or chemical? Explain.
Cutting is a physical change because it
changes the shape of the material but does
not change the kind of material itself.
Burning is a chemical change because it
changes into a new kind of material.
How is a chemical property different than a
physical property?
Chemical properties describe a substance’s
ability to become a new substance.
For Example:
Water turns to vapor = new substance = chemical change.
Ice turns to liquid = new substance = chemical change.
Cake batter turns to cake = new substance = chemical change.
Jell-O sugar crystals turn to solid Jell-O = new substance =
chemical change.
Cooking an egg causes new kinds of matter
to form. Take a look at the illustration
on P. 302. Which material in the picture
undergoes a chemical change when heated,
the egg or the frying pan? Explain.
The egg because it changes from a raw egg
to a cooked egg. Therefore, a chemical
change happens to the egg.
What type of change occurs when a raw egg
is boiled?
Chemical, because new kinds of matter are
formed.
What are we supposed to learn from this
lesson?
Every hand should be in the air by now!!!
The Difference Between Physical
and Chemical Properties!!!