Chapter 3: Matter and Energy
Date:____________
Section 2: Changes in Matter - Notes
Objectives:
 Distinguish between physical and chemical properties.
 Distinguish between physical and chemical changes.
 Apply the law of conservation of mass.
Properties of Matter:
 Physical property: a property that a substance displays without __________________________
_______________________________________.
o

Includes:
Chemical property: a property that a substance displays only through _____________________
_______________________________________.
o

Includes:
Example: Gasoline
o
Physical property: _________________________________________________________

gasoline does not ____________________________________________ when it
exhibits its odor
o
Chemical property: __________________________________________

gasoline does _______________________________________________ when it
burns

The __________________________________________________________ of a substance does
not change when the substance displays its physical properties.

A chemical or physical property can also be described as either _________________________ or
____________________________.

Intensive Properties: Properties that do not depend on the ______________________________
___________________________________.
o
Examples:

Extensive Properties: Properties that do depend on the ________________________________
____________________________________.
o
Examples:
Changes in Matter:

Physical property: the boiling point of water
o
How is the water changing once it boils?

When water boils, it turns into ______________, but the water molecules are
the __________ in both the _____________________________ and the
_______________________________.

Physical change: matter changes its appearance but ___________________________________
o
When ice melts, it looks different but its _______________________________________
is the same. Solid ice and liquid water are both composed of ______________________
molecules, so melting is a physical change.

Chemical change: matter does change _________________________________________
o
For example, copper turns green upon continued exposure to air because it reacts with
gases in air to form __________________________________. This is a chemical change.

State changes: transformations from one state of matter to another, such as from solid to liquid
o

These are _________________________________________________
Condensation

o

Freezing
o

o

Melting
o
Evaporating
Sublimation
o

Deposition
o

Physical changes include:

Four good indications of a chemical change:

A chemical property: The susceptibility of iron to rusting.
o
Is rusting a physical or chemical change?


Practice:
o

When iron rusts, it turns from ________________________________________.
Classify each property as physical or chemical.
a) the tendency of copper to turn
green when exposed to air
c) the tendency of gasoline to
evaporate quickly when spilled
b) the tendency of automobile
paint to dull over time
d) the low mass (for a given
volume) of aluminum relative
to other metals
Matter undergoes a chemical change when it undergoes a ______________________________
_________________________________.

In a chemical reaction, the substances present before the chemical change are called
___________________. The substances present after the change are called ________________.

The difference between chemical and physical changes is seen at the ______________________
__________________________________.

In physical changes, the atoms that compose the matter do not change their
______________________________________________, even though the matter may change
its _______________________________.
o
A physical change results in a __________________________________ of the
_______________________________.

In chemical changes, atoms do change their __________________________________________,
resulting in matter with a ________________________________.
o

A chemical change results in a ______________________________________________.
Practice:
o
Classify each change as physical or chemical.
a) the rusting of iron
b) the evaporation of fingernail-polish remover (acetone) from the skin
c) the burning of coal
d) the fading of a carpet upon repeated exposure to sunlight
Separation of Mixtures:

Compounds are ___________________________________________
o

Mixtures can never consist of only a ____________________________________________
o

Compounds can only be separated by _________________________________________
Mixtures can be separated by _______________________________________________
Filtration
o
Separates ______________________________________
o
The mixture is poured over a mesh-like filter paper and the
___________________ is allows to pass through, leaving behind
the _________________

Density
o
Liquids of ____________________________________________
will separate into layers.
o
The lowest density liquid will _______________________________.

Centrifuge
o
A centrifuge is a machine that separates _______________________________________
by spinning very quickly.
o
This causes _________________ to fall to the bottom of the test tube, separating them
from the liquids in the mixture.

Decant
o
Separates ___________________________________ by pouring the liquid off the top
and leaving the solid behind
o


It can be difficult to ensure that all of the ______________ is removed by this technique
Magnetism
o
Can be used to remove ______________________________________ from a mixture
o
Magnetic elements include ______________________________________________
Distillation
o
To separate a _____________________________________, the liquid can be heated to
force components, which have different ______________________________________,
into the gas phase. The gas is then ______________________________ back into liquid
form and collected.
o
Can be used to separate several different substances

Chromatography
o
Techniques which use a _______________________________________ (e.g. paper) and
a ________________________________ (e.g. some sort of solvent like water or alcohol)
to physically separate substances.
o
A sample of the mixture is placed on the paper (stationary phase). The solvent will then
______________________________ the components of the mixture.
o
The components of the mixture will __________________ with the solvent (mobile
phase) up the paper.
o
Based on the ______________________________ of each component (e.g., polarity)
the components will travel at different ________________________ with the solvent.
o
Many complex variations, but basic principles stay the same
Law of Conservation of Mass:

Law of Conservation of Mass: matter is neither created nor destroyed in a
________________________________________.
o

In a _____________________________________, significant changes in mass can occur.
During physical and chemical changes, the total amount of ______________________________
______________________________________.

Suppose that we burn 58 g of butane in a lighter. It will react with 208 g of oxygen to form 176 g
of carbon dioxide and 90 g of water.
Practice:

A chemist forms 16.6 g of potassium iodide by combining 3.9 g of potassium with 12.7 g of
iodine. Show that these results are consistent with the law of conservation of mass.

Suppose 12 g of natural gas combines with 48 g of oxygen in a flame. The chemical change
produces 33 g of carbon dioxide. How many grams of water form?