Grade 9 Academic Science – Chemistry
Particle Theory and Physical Properties of Matter
Section 5.1 and Section 5.2
Matter is anything that has mass and takes up space.
NOTE: In the entire universe, anything . can be classified as either matter or energy.
The Particle Theory of Matter
1. Matter is made up of tiny particles: atoms and molecules
2. Particles of matter are in constant motion
3. Particles of matter are held together by very strong electrical forces
4. There are empty spaces between the particles of matter that are very large compared to the
particles themselves.
5. Each substance has unique particles that are different from the particles of other substances
6. Temperature affects the speed of the particles. The higher the temperature, the faster the speed of
the particles.
The particle theory of matter explains the following scientific phenomena.
1. Pure substance are homogeneous (one phase - one unique kind of particle)
2. Physical Changes such as melting, evaporating, sublimating, dissolving, etc.
3. Physical Properties including density, viscosity, electrical conductivity, thermal conductivity,
boiling point, melting point, etc.
We are concerned mainly with the three primary states of matter: (1) solid, (2) liquid and (3) gas.
Task

Use your textbook to complete Table 1.
Table 1. Physical Properties of Each State of Matter
Property
Solid
Liquid
Gas
Shape
Volume
Ability to flow
Can be compressed
Volume change with
heating
Physical Properties
 A physical property is a characteristic of a substance that can be determined without changing the
composition of the substance.
 They can be either qualitative (not measurable, descriptive) or quantitative (measurable such as
mass)
Table 2. Examples of Physical Properties
Physical State
Solid, liquid, gas
Colour
Green, blue, yellow, reddish-brown, etc
Odour
Odourless, spicy, nauseating, etc.
Clarity
Ability to let light through - clear, cloudy, opaque
Lustre
Shiny, dull
Form
Regular (crystalline), irregular (amorphous)
Texture
Fine, coarse, smooth, waxy, etc.
Hardness
Ability to be scratched easily…scale 1-10 (e.g., diamond – 10)
Brittleness
Ability to break apart / Shatter easily
Malleability
Ability to be folded into different shapes
Ductility
Ability to be stretched
Viscosity
Ability to flow or pour readily
Electrical
Conductivity
Ability to allow electric current to pass through it
Properties of Matter
1.
Match the description with each of the physical properties listed below by placing the appropriate
letter in the blank
_________ “feel” of a substance
A. Physical state
_________ hammered into a sheet
_________ ketchup stuck in a bottle
_________ ice
_________ a frosted window in a bathroom
_________ fermented milk
_________ stretching gold into a thin, long wire
_________ sour, sweet and salty
_________ a diamond reflecting light
_________ a diamond etching in glass
_________ copper burning green when in a flame
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
Odour
Clarity
Texture
Viscosity
Malleability
Taste
Hardness
Colour
Lustre
Ductility
2.

Write the physical property beside each of the following
The sheet of glass is clear

The sandpaper feels rough

The milk tastes sour

The cold syrup flowed very slowly

The powder is blue-gray

Her perfume is very strong

The molten steel was stretched into a wire

Mercury is a liquid at room temperature

The sheet of gold foil was hammered very
thin by the artist

The diamond sparkled brilliantly
3. Describe each of the following objects using three different physical properties
A pearl
A snowflake
A lemon
Aluminium foil