Transcript Matter_Properties and Changesstudent

Chemistry
Chapter 3
Properties and Classification
of Matter
Chemistry-Matter and Change
Glencoe
Last revision Fall 2007
Matter
Matter – anything that has mass and volume.
Mass – the amount of material that makes an
object
Volume – the amount of space an object takes
Your textbooks?
Light from
a
lighthouse?
The pen/pencil you
are writing with?
Your thoughts?
Heat from
a fire?
All matter is made of tiny little particles called
atoms.
There are 90
different naturally
existing atoms and
25 man made ones.
They can all
be found
on the
periodic
table.
Everything about you and everything around you is
made of these atoms or combinations or mixtures of
these atoms.
For example:
Water (H2O)
2 hydrogen atoms
& 1 oxygen atom
Salt (NaCl)
1 sodium atom &
1 chlorine atom
Properties of Matter
Physical Property - a quality or condition of matter that
can be observed or measured without changing the
arrangement of atoms that make it
Examples:
•Mass
• color
•Length
• size
•Volume
• shape
•Boiling point
• state of matter
•Melting point
• texture
These properties can usually be observed using our
senses or measured with equipment in the lab.
Chemical Properties – property that can only
be observed when the arrangement of
particles that make the matter are altered
These properties usually tell you how a
substance will react in the presence of a
second substance.
Examples:
Iron reacts with oxygen to form rust.
Metals react with acids to form hydrogen
gas.
Changes in Matter
Physical Changes – changes in matter that do not
alter the arrangement of atoms that make the
matter
Changes in size, shape, and STATE OF MATTER.
Examples:
crumpling up a piece of paper
breaking a stick in half
melting ice
salt dissolving in water
Chemical Changes - changes in matter that DO
alter the arrangement of atoms that make
the matter
Because you can’t see the particles to
determine if arrangement has changes, you
can look for clues that tell you a chemical
change has occurred.
Clues of a Chemical Change:
Identify the following as either a physical property
or a chemical property.
Property
a shirt is red
sodium is so soft it can be
cut with a knife
potassium reacts vigorously
with water
paper is flammable
water boils at 100 oC
Physical
Chemical
Identify the following as either a physical change or
a chemical change.
Change
burning toast
breaking a glass
melting butter
leaves changing color
fireworks exploding
Physical
Chemical
Intensive vs. Extensive
Intensive properties are properties unique
to a pure substance. It is a property that
can be used to identify it.
Ex:
 Extensive properties are properties that
many kinds of substances can have and will
not identify the substance.

Now that we can describe matter,
we can begin to classify it
Matter-anything with mass and volume
Matter is separated into two categories: pure
substances and mixtures.
Matter
Pure Substance – a substance made of the
same kind of atoms or compounds having a
unique set of chemical and physical
properties
The two categories of pure substances are
elements and compounds
Pure Substance
Element
 simplest type of pure substance
 made of only 1 kind of atom
Examples:


all particles are identical
cannot be separated by a physical or a
chemical change
Compounds
 made of two or more different kind of
elements chemically combined
together in a specific ratio
Examples:

elements in a compound can only be
broken apart by a chemical change
Classify the following as either an
element or a compound.
Mixtures
 physical blend of two or more pure
substances.
 can be separated by a physical change
The two categories of mixtures are
homogeneous and heterogeneous.
Mixtures
Homogeneous Mixtures
 mixtures that are uniform in composition on the
atomic level.
 all parts of the mixture have the same
concentration of matter.
 Different parts of the mixture can not be
identified (transparent appearance for solutions)
 Alloys: solution of metal
 also called a solution
Examples:
Salt water, vinegar
Lemonade, alcohol
3% H2O2 and H2O solution
Steel, solder or 14 K gold
Heterogeneous Mixtures
 mixtures that are not uniform in
composition
 all parts of the mixture are not the same
 the different parts can usually be easily
identified from one another
Examples:
rocks and sand
salt and pepper
oil and water
Classify the following as either a
homogeneous mixture or a
heterogeneous mixture.
Classify the following everyday
common objects as a homogeneous
mixture or a heterogeneous mixture.
Jelly
Soda
Pizza
Mixed Nuts
Lotion
Chunky Peanut Butter
Matter
Pure Substances
Element
Compound
Mixtures
Homogeneous
Heterogeneous
State of Matter- Matter can be solid, liquid,
gas or plasma depending on how much kinetic
energy (or motion) they have.




Solid: Particles vibrate in place. It has a definite
volume and a definite shape.
Liquid: Particles roll around each other. It has a
definite volume but no definite shape.
Gas: Particles move around colliding with one another.
It has no definite volume or shape.
Plasma: Particles are so hot and excited that the
electrons leave the nucleus and matter is ionized or
charged
Matter in Motion

The Kinetic Molecular Theory states
that atoms and molecules are always
in motion.
Remember, the temperature of a substance
is the measure of its kinetic energy.
That energy can only do one thing at a time:
1. Change the state of the substance.
2. Increase the temperature of a substance.
1. Changes in the states of Matter
Boiling
Condensing
Sublimating
Melting
Depositing
2. Heating Curve
This curve can also work
in reverse if energy is
being taken away.


Absolute
Zero
is the
temperature at
which all
motion of
particles stops.
Scientists have
yet to reach it.
Separating Mixtures
Mixtures
are physical blends of two or
more pure substances.
Since
they are mixed physically, they can
be separated into the individual pure
substances by physical changes.
Compare and Contrast the two types of mixtures.


Contrast
Compare

Contrast
using:
Freezing and Boiling
Points
Example: Separate alcohol
and water
Distillation - method of separating components of a solution
using their boiling points.
•
involves 3 stages and both are state of matter changes
(1) The solution is boiled to
vaporize
one component
of the
solution with the
lower boiling
point.
(2) As soon as the temperature
starts
to rise, the vapor stops
being
collected since this rise
in
temperature indicates the
end of
a phase change.
(3) The vapor is cooled to
turn it
back into a liquid
1.
2.
3.
Example: Separate sand and salt.
Solubilit
yDissolve substance that is soluble in
water.
Filtration - uses a filter of porous material
to separate a mixture of liquid and
insoluble components
Evaporate the liquid portion of a solution
which changes to a gas or vapor leaving a
solid behind
Magnetism - used to separate components of a
mixture when one is attracted to a magnet and
one is not
Chromatography - method of separation used to
see what colors make up an ink or substance
containing different molecules.
Steps of Chromatography
1. Material to be separated
is spotted on
chromatography paper
2. Paper is dipped into a
solution that will be
absorbed by the paper
and moves up
3. Some colors move more
than others and separate