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Matter
chapter 3
Matter
Anything that has mass and occupies
space
– Mass is measured in grams or
kilograms
– Space or volume is measured in
liters or cm3
Phases
• SOLIDS
• LIQUIDS
• GASES
Solid:
•definite volume
•definite shape
Liquid
• definite volume
• indefinite shape
• takes the shape of container
Gas
•indefinite volume
•indefinite shape
•takes the shape and volume
of container
States of Matter
1. How are the particles packed in each
phase?
2. How do the particles move in each phase?
3. Why do liquids and gases flow?
4. Why are gases so easy to compress?
th
4
Phase of matter
• Plasma
• exists in stars
• electrons are stripped from
atoms
Physical Properties
• Describe the appearance and
form of matter
Words:
• color, texture, luster, odor, solid,
liquid, gas
Measurements:
• a number and a unit
Intensive properties
– Physical Constants
– independent of sample size
• Density, freezing point, and
melting point
• Solubility in water (g/ml)
Extensive Properties
• Mass  volume
• depends on amount of matter in
sample
• Extensive properties depend on
quantity of matter
Chemical Properties
• Describe how matter behaves in
presence of other matter
• Describe how matter changes
into another kind of matter
– Flammability
– Resistance to corrosion
– Ability to neutralize acids or bases
Properties of Copper
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Physical Prop.
Reddish brown
Shiny
Malleable
Ductile
Good Conductor
Density = 8.92 g/cm3
mp = 1085C
bp = 2570C
Chemical Prop.
• Reacts to form
green copper
carbonate
• Forms a deep blue
solution when in
contact with NH3
• Forms new
substances with
HNO3
Physical Change
• The form or appearance of sample
may change but identity remains
same
– Cutting, crushing, grinding,tearing
– Phase changes
– Dissolving
Dissolving
• Dissolving is physical change
• Think of sugar in water
• still have sugar – you just spread it
out with water molecules in
between
C6H12O6(s)  C6H12O6(aq)
Phase Changes
• Phase changes are physical changes
• No new substance is created
(chemical formula stays the same)
Ex:
• ice melting: H2O(s)  H2O(l)
• water boiling: H2O (l)  H2O(g)
Chemical Change
• chemical change - identity of
matter is changed
• new substance with unique
properties is formed
• The chemical formula changes
• Ex: 2H2O(l)  2H2(g) + O2(g)
Burning
• Common name for oxidation reaction
• Burning means reacting with oxygen
• Burning is chemical change, because
original substance is changed into new
kinds of matter
Ex:
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)
What kinds of matter are
there?
Matter
Substances
Elements
Compounds
Mixtures
Heterogeneous
Mixtures
Homogeneous
Mixtures
Mixtures  Separated by physical methods
Compounds  Separated by chemical methods
Element
• Substance that:
• cannot be broken down or decomposed
into simpler substance
• only 1 kind of atom
• has definite properties
• Formulas have 1 uppercase letter
Element Song
Atom
• smallest particle of element that
retains properties of element
• smallest particles of element that
can undergo a chemical reaction
Compounds
• 2 or more elements chemically combined in
a definite ratio
• Properties are different from those of
elements formed from
• Homogeneous
• Broken into elements by chemical
decomposition reaction
• Formulas have 2 or more uppercase letters
2Na + Cl2  2NaCl
Mixtures
• Combo of 2 or more pure substances
• Physically combined not chemically
combined
• Each substance retains its own
identity and properties
Mixtures
• Variable composition
• No unique properties
(Think of sugar and salt mixed together)
• Separated by physical methods
• May be homogeneous or heterogeneous
Types of Mixtures
• Homogeneous: constant composition
throughout, single phase
– Ex: Solutions (all 3 phases)
such as air, windex, kool-aid
• Heterogeneous: See a boundary or
regions that look different
Ex: ice water, granite
Suspensions, Colloids
Suspensions
• particles in suspensions are larger than
those in solutions
• components of suspension can be evenly
distributed by mechanical means (shaking
the contents) but components will settle out
Colloids
• particles larger than size of molecule but
smaller than particles seen with naked eye
• colloidal dispersion
– consists of colloids in a dispersing medium
• Ex: whipped cream, mayonnaise, milk,
butter, gelatin, jelly, colored glass
Colloid subtypes
Aerosols:
–solid or liquid particles in
gas
Ex:
•Smoke: solid in a gas
•Fog: liquid in a gas
Sols:
–solid particles in a liquid
Ex:
•Milk of Magnesia (solid
magnesium hydroxide in
water)
Emulsions:
–liquid particles in liquid
Ex:
•Mayonnaise: oil in water
Gels:
–liquids in solid
Ex:
•Gelatin: protein in water
•Quicksand: sand in water
Hints for Mixtures
• Solutions in gas & liquid phases
transmit light
• particles not big enough to scatter light
• look translucent
• Suspensions look cloudy
• particles big enough to scatter light
• settle on standing
CuSO4(aq)
source
source
Particle Diagrams
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
Atoms of a
monatomic
element
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

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Molecules of
a diatomic
element
Particle Diagrams
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  
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
Molecules of a
triatomic
compound
Mixture:
monatomic element,
diatomic element,
triatomic compound
Separating Mixtures
• Physically combined
• Separation based on physical properties
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–
–
–
–
–
Sorting: size & appearance
Filtration: size solid in liquid
Distillation: different bp’s liquids mixed
Crystallization: solubility solid in liquid
Magnet: magnetization
Chromatography: solubility liquids mixed
– “Travel” ability
source
Distillation
Paper Chromatograhy
Crystallization
Conservation of Mass
Mass before = Mass after
# of atoms before =
# of atoms after