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Basic Concepts of Matter
Chapter 4
Chemistry
  The science devoted to the study of matter, its
composition, its structure, its properties, and the changes it
undergoes (via reactions).
  Matter:
  anything that occupies space and has mass
  Mass
  pertains to the quantity of matter that an object has
  unaffected by location
  defined as resistance to acceleration
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Weight:
  results from the force that gravity exerts
  since the force of gravity can vary depending on location,
weight (unlike mass) can vary with location
  eg: consider the weightlessness of an object on the moon
but its mass does not change
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Composition and Structure of Matter
  Composition:
- identity and amount of each component
water, H2O
  Structure:
- manner in which the components are put together
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Physical States of Matter
  solid:
-non compressible
-definite shape and volume
  liquid:
-slightly compressible
-flows
-indefinite shape
-definite volume
  gas:
-readily compressible
-indefinite shape and volume
-takes shape of the container
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Changes of State
  Process of changing from one physical state to another
  melting
 
solidification (or freezing)
 
evaporation (or boiling)
 
condensation
 
sublimation
 
deposition
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Properties of Matter
  characteristics that enable us to distinguish one substance
from another
  Extensive Properties
  a property that depends on the amount of substance
present
  Intensive Properties
  a property that is independent of the amount of
substance
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Properties of Matter:
  Physical properties:
-properties that can be observed without the substance
changing into another substance(s)
  Chemical properties:
-properties that matter exhibits as it is undergoing a change
in chemical composition, or as it resists a change in
chemical composition
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Physical /Chemical Change
  Physical Change:
-no change in the chemical composition of the matter
  Chemical Change:
-involves a change in chemical composition
-always produces at least one new substance
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Property vs. Change
  Physical Change
melting
boiling
compression
dissolution (dissolving)
process that involves a
transformation from one
form to another but the
substance identity remains
the same
  Physical Property
melting point
boiling point
density
solubility
characteristic used to
distinguish one
substance from another
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Chemical change or Physical change?
A)  The alcohol in a thermometer rises with increasing
temperature
B)  A copper church steeple turns malachite green
C)  A twig is mashed up with a hammer
D)  A grease spot is dissolved with petroleum
E)  A cake bakes in the oven
How do we know if a chemical change has taken place?
Evidence of chemical change:
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Classification of Matter:
  Pure Substance:
-single kind of matter
-definite and constant composition
-identical composition and properties throughout sample
  Mixture:
-physical combination of two or more pure substances
-varied properties
-composition may vary from sample to sample
-chemical identity of the individual components is
maintained
-some mixtures can be separated into pure substances
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Types of mixtures
  Homogeneous mixture
- has only one phase
- uniform properties in a sample
- same composition in a sample
  Heterogeneous mixture
- 2 or more phases (with same or different physical
states)
-  each phase has different properties
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Phase
  In a system of two or more phases, each phase is a visibly
different part which has different properties
  The variation in properties may be :
- different physical properties in each phase
- different chemical properties
- different physical and chemical properties
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Physical Separation Techniques
  By eye
  Filtration to separate solid and liquid
  Distillation to separate two or more liquids with different
boiling points
  Selective condensation to separate gases with different
condensation temperatures
  Chromatography to separate pure liquids or solutions of
compounds
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Filtration
Laboratory filtration
of a heterogeneous
mixture
Water filtration plant
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Distillation
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Column Chromatography
Paper Chromatography
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Types of pure substances:
  Element
- cannot be broken down into simpler substances by
ordinary chemical means
eg: iron, silver, oxygen, gold
  Compound:
- can be broken down into 2 or more simpler
substances
- ultimately broken down to elements
- a compound is not a mixture
electric
current
H 2O ⎯
⎯ ⎯
⎯→ H 2 + O2
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Practice
1. Classify each as an element, compound, homogeneous
mixture, or a heterogeneous mixture:
a) 
b) 
c) 
d) 
e) 
f) 
g) 
Seawater
Helium gas
Sodium chloride (table salt)
A soft drink
A milkshake
Air
Concrete
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Elements
  In principle all matter can ultimately be broken down into
one or more of over 109 different elements (112 known,
88 occur naturally)
  The building blocks of all matter: elements, compounds,
pure substances, mixtures
  Represented in the Periodic Table
  Symbols can be equated to the alphabet of a new language
  Put together to form words (chemical formula) and then
sentences (chemical equations)
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The Periodic Table of the Elements
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Interactive Periodic Table
SFU Chemistry Dept 9000 Level
Interactive Periodic Table
Know the Elements
  For the first midterm: February 7th
 
know the names, symbols and position in the Periodic
Table of the first 36 elements
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Classification of Matter
Matter
Mixtures
physical
methods
Heterogeneous Homogeneous
Mixtures
Mixtures
Pure Substances
Compounds
Elements
chemical
methods
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