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
 Hetrogeneous Mixtures
 Solution
 Homogeneous Mixtures
 Mechanical Mixture
 Suspension
 Solution
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Pure Substances
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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’S ALL MATTER!
The Particle Theory of Matter
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This describes the 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.
 These 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
The Particle Theory of Matter
 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
 Pure substances are in the form of either elements or
compounds.
Elements
 Elements are the smallest and “Purest”
forms of particles
 They cannot be broken down further by
ordinary means (such as simple
reactions, heat, or electricity)
 They are only made up of one type of
atom (one type of particle
 Examples are Oxygen, Calcium, Iron,
Carbon and Helium
Compounds
 A compound is made up of only one type of particle,
Called a molecule
 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
substances (different types of particles).
 Mixtures can be divided into 2 big categories:
 Heterogeneous Mixtures
 Homogeneous Mixtures
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
 Particles that are in the same container but can be easily
separated.
 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
 Small particles of one
substance float in another
substance
Salad Dressing,
glittery nail polish,
and yogurt are
examples of
suspensions
Homogeneous Mixtures
 A homogenous mixture
occurs when 2 or more
particles blend together and
cannot be seen separately
 Solutions are homogeneous
mixtures!
Solutions
 A mixture of 2 or more
things where one substance
dissolves
 Kool-Aid and tea are
solutions because you cannot
see the flour crystals floating
in the kool-aid, and you
cannot see the tea floating in
the tea when the bag is
removed
Kool-Aid and tea
are examples of
solutions