Grade 9 Science– Notre Dame College School
 John Dalton – the guy who came up
with particle theory
Agenda
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What is matter
The Particle Theory
Mixtures vs. Pure Substances
Mixtures
 Heterogeneous Mixtures
 Solution
 Homogeneous Mixtures
 Mechanical Mixture
 Suspension
 Solution
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Pure Substances
Elements
Compounds
What is Matter?
 Matter is anything that contains mass & volume (takes
up space)
 Energy, such as light, heat, and sound, is NOT matter
IT ALL MATTERS!
The Particle Theory of Matter
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This provides a way to describe the structure and
behaviour of matter.
There are 4 principals of the particle theory written
by a chemist named John Dalton.
Think About it!
Look at a piece of chalk  If you broke a piece
of chalk in half, would it still look like and behave
like chalk?
How small of pieces would you have to break a
piece of chalk so that it isn’t chalk anymore – is that
even possible?
The answer is YES, because the smallest pieces
of chalk are made up of particles and the particle
theory explains how this works!
The Particle Theory of Matter
1. All matter is made up of very tiny objects
called particles.
 These particles are VERY tiny – too small to be
seen with any regular light microscope
The Particle Theory of Matter
2. All Particles have
spaces between them.
 The size of these spaces
determine the state of the
matter
The Particle Theory of Matter
3. Particles present in matter are always in motion.
 In a solid, they vibrate together
 In a liquid, they stay close together but slide
along each other
 In a gas, they bounce and move in all directions!
The Particle Theory of Matter
4. The particles in a substance attract each other.
 The degree that particles are attracted to each
other is different in difference substances,
Take a guess!
 Which substance do you think has the strongest
attractions? Which has the weakest?
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Iron
Water
Oxygen
http://www.youtube.com/watch?v=I9xB4hhWvXY
 Recap: Here they are all again
All matter is made up of very tiny objects called
particles.
2. All particles have spaces between them.
3. Particles present in matter are always in motion.
4. The particles in a substance attract each other.
1.
Pure Substances vs. Mixtures
 All matter can be divided into two big categories:
PURE SUBSTANCES and MIXTURES.
 Pure substances are made up of one type of element
or compound
 Mixtures are a combination of pure substances (2 or
more types of particles)
Versus
Pure Substances
 Pure substances are made up of only ONE type of
particle or matter, and has a unique set of
properties.
 Pure substances are in the form of either elements or
compounds.
Elements
 Element- a substance that cannot be
broken down into any simpler
substance by chemical means.
 They are only made up of one type of
atom (one type of particle)
 Examples are Oxygen, Calcium, Iron,
Carbon and Helium (see periodic table)
Compounds
 A compound is a pure substance that is made from two
or more elements that are combined together
chemically.
 Compounds are made up of many molecules that are
held together by chemical bonds!
Hydrogen
Oxygen
Hydrogen
 Water is a molecule
because it is made
out of two types of
atoms (oxygen and
hydrogen)
Water is a compound
because it has many
molecules of one type
(H2O = Water)
Mixtures
 A mixture is a combination of two or more different
pure substances (different types of particles). They do
not chemically combine.
 Mixtures can be divided into 2 big categories:
 Heterogeneous Mixtures (Mechanical)
 Homogeneous Mixtures (Solutions)
Heterogeneous Mixtures
 Made up of two or more particles
where the different particles are easy to
see and separate.
 Can be divided into two categories:
 Mechanical mixtures
 Suspensions
An Oreo cookie is a
heterogeneous mixture
Mechanical Mixtures
 the different substances that make up the mixture are
visible.
 Made up of several distinct parts
A lasagne, parfait,
and a cookie are
both examples of
mechanical
mixtures
THINK ABOUT IT!
What are some of the
parts of these
mechanical mixtures?
Suspensions
 A cloudy mixture where small
particles of one substance are
held (float) in another
substance
 These particles can be
separated by filtration.
Salad Dressing,
glittery nail polish,
and yogurt are
examples of
suspensions
Homogeneous Mixtures
 A homogenous mixture
occurs when 2 or more
particles dissolve in one
another.
 Only one layer of phase is
visible.
 Solutions are homogeneous
mixtures!
Solutions
 A mixture of 2 or more
substances that dissolve in
each other. Only one layer or
phase can be seen.
 Kool-Aid and tea are
solutions because you cannot
see the sugar crystals
floating in the Kool-Aid, and
you cannot see the tea
floating in the tea when the
Kool-Aid and tea
bag is removed
are examples of
solutions
Atom
The smallest particle of an element is the atom
Elements - molecule
2
2 atoms of hydrogen bonded together
Compound - Molecule
2 or more different types of atoms bonded
together. Many molecules make a
compound
Which Is It? (element, compound
or mixture)
ELEMENT
Which Is It?
COMPOUND
Which Is It?
MIXTURE