CHEMICAL PROPERTIES
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Transcript CHEMICAL PROPERTIES
CHEMICAL
PROPERTIES
7TH Grade Science
Mrs. Hartley
CHEMICAL PROPERTIES
Chemical
Properties describe matter
based on its ability to change into new
__matter that has different
______properties______________.
Example: When wood is burned,
__ash_____ and ___smoke__are created.
__Flamability_is the ability of a substance
to burn.
CHEMICAL PROPERTIES
Reactivity:
__ is the ability of two or more
______________ to combine and form two
new _____________________.
EXAMPLE: Iron is exposed to
______________, it rusts.
COMPARING PHYSICAL AND
CHEMICAL PROPERTIES
How
can you tell physical properties from
chemical properties?
PHYSICAL PROPERTIES DO NOT ________THE
IDENTITY OF THE SUBSTANCE.
EXAMPLE: You can find the density and
hardness of wood without changing the
wood.
COMPARING PHYSICAL AND
CHEMICAL PROPERTIES
Chemical
properties are not as easy to
observe!
EXAMPLE: Wood is flammable only while
it is burning.
EXAMPLE: Wood has the chemical
property of flammability EVEN WHEN IT IS
NOT BURNING!
CHARACTERISTIC PROPERTIES
Characteristic
Properties: most useful in
identifying a substance.
Examples:
Density
Solubility
_______________
_______________
CHEMICAL CHANGES AND
NEW SUBSTANCES
CHEMICAL
CHANGE: When 1 or more
substances are changed into
_________substances.
Examples:
Fireworks
_________________
_________________
_________________
WHAT HAPPENS DURING A
CHEMICAL CHANGE?
One
way to see what happens during a
chemical change is to
_______________________________.
You can see all the ingredients producing
a new product/substance.
SIGNS OF A CHEMICAL
CHANGE
Change
in color or odor
Production of heat
Fizzing and foaming
Sound or light being given off
_________________________
_________________________
MATTER AND CHEMICAL
CHANGES
Chemical
changes change the
____________of the matter involved.
So, most chemical changes would be
hard to ______________.
However, some chemical changes can
be reversed by more ____________
_______________.
EXAMPLE: ______________________________
CHEMICAL CHANGE MINI LAB
Steel
Wool + Hydrogen Peroxide =
______________________________________
What did you observe?
_________________________________________
_________________________________________
_________________________________________
_________________________________________
_________________________________________
PHYSICAL VS CHEMICAL
CHANGES
Most important question to ask yourself when
trying to decide if it is a physical or chemical
change
is___________________________________________
____________________________________________
_________________________________.
The composition of an object is the type of
matter that makes up the object and the way
that the matter is arranged in the object.
LOOK AT FIGURE 5 – pg. 20
A CHANGE IN COMPOSITION
Physical
changes do NOT change the
_________________of the substance.
Chemical changes do ALTER the
________________________ of a substance.
EXAMPLE:
Electrolysis:_____________________________
_________________________________________
_________________________________________
REVERSING CHANGES
Can physical and chemical changes be
reversed?
MANY ________________changes are easily
reversed.
They do not change the composition of the
substance.
BUT MOST chemical changes would be
impossible to reverse.
EXAMPLE: Fireworks, Burning a piece of wood,
____________________, _______________,
____________________. _____________________.
I CAN STATEMENTS…
I
can tell
you_____________________________________
________________________________________.
I can tell you
_________________________________________
________________________________________.