Unit 1-3 Matter
Key terms in this unit
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Material
Mixture
Phase
Heterogeneous mixture
Interface
Homogeneous
Solution
Solute
Solvent
Substance
Element
Compound
Organic substance
Inorganic substance
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Physical change
Chemical change
Precipitate
Physical property
Chemical property
Extensive property
Intensive property
System
Heat
Joule
Endothermic
Exothermic
Activation energy
Calorimeter
Specific heat
Heterogeneous Materials
• The word Material is used when referring to a
specific kind of matter, such as wood, steel ,
air, copper, sugar, salt, nickel, marble, concrete
or milk.
• A Mixture is matter that contains two or more
different materials.
• Any physically separate part of a material is
called a Phase. A phase is any region with a
uniform set of properties.
Example: Granite
• Granite is a material.
• It is a mixture because it
contains the minerals
quartz, biotite and
feldspar.
• Each of the different
minerals in granite is a
separate phase because
each is a separate part of
the material with
individually uniform
properties.
Thin section
Ha
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Heterogeneous Materials
• Ice and water are different
phases of the same
material. In a glass of ice
water, all of the water has
the same set of properties
and all of the ice has the
same properties, but the
ice and the water do not
have all the same
properties.
Heterogeneous Materials
• A heterogeneous mixture is a mixture that is
composed of more than one phase.
• The different phases in a heterogeneous
mixture are separated from each other by
definite boundaries called interfaces.
• For the ice water example the interfaces are
the surfaces of the ice cubes that are touching
the liquid water.
Homogeneous Materials
• Materials that consist of only one phase are
called homogeneous materials. When a piece
of homogeneous material that is broken down
into smaller pieces, the smaller pieces will all
have the same properties as the original
material. Even under a microscope, you will
not be able to distinguish different phases.
Homogeneous Materials
• Examples
Homogeneous Materials
• Examples
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Sugar
Salt
Seawater
Quartz
Window glass
Air
Homogeneous matter and solutions
• Heterogeneous matter is always composed of
more than one phase and is always a mixture.
• If homogeneous matter is composed of more
than one material it is called a solution. How
can homogeneous matter be composed of
more than one material?
Solutions
• A solution consists of a solute (dissolved
material) in a solvent (dissolving material). In
the case of two liquids in solution, the solvent
is the component that is in the larger
proportion of the whole solution.
Solutions
• The solute is scattered
in the solvent as very
small particles. Thus,
the solution appears
uniform m even under
the most powerful
optical microscopes.
I cant see anything…
Matter
Pure Substances
• Pure substances have the same composition at all any
level.
• Pure substances composed of only one kind of atom
are called elements. Examples of elements include
oxygen, hydrogen, gold, silver and sulfur.
• Pure substances composed of two or more kinds of
atoms are called compounds.
• Substances can also be categorized as either organic or
inorganic. An organic substance contain the element
carbon.
• Inorganic substances do not contain the element
carbon.
Types of changes
• Physical Change – A
change from one form
to another without a
change in chemical
properties.
• Examples: Changes of
state(melting, boiling,
etc.) cutting, tearing,
water changing into ice
• Chemical Change – A
change that occurs
when one substance
changes into another
substances with
different properties.
• Examples: Burning,
rusting, water changing
into H2O2.
Precipitate
When a substance comes out of solution it is
called a precipitate. The forming of a precipitate
can be forced by reducing the amount of solvent
through evaporation.
Types of Properties
• Physical Properties – color, length,
temperature, etc.
• Chemical Properties - what a substance reacts
with (or doesn’t react with) and how it reacts.
• Extensive Properties – depend on the amount
of matter present. (Mass, length, volume, etc.)
• Intensive Properties – do not depend on the
amount of matter present. (density,
malleability, ductility, conductivity, etc.)
Energy
• Physical and Chemical Changes are always
accompanied by energy changes. The energy
changes occur between a system and its
surroundings. A “system” is the portion of the
universe we are considering. Everything in the
universe is either in the system or outside the
system.
• When energy is transferred between two objects,
the energy transferred is called heat.
• The SI unit of heat is the joule (J).
Energy
• Endothermic – a reaction where the system absorbs
energy from the environment.
• Exothermic – a reaction where the system transmits
energy to the environment.
• Activation energy – the minimum amount of energy
required for a reaction to take place.
• Calorimeter – a device used for measuring the amount
of energy given off or absorbed during a physical or
chemical change.
• Specific Heat – the amount of energy needed to raise
the temperature of 1 gram of a substance by 1 degree
Celsius.