Chapter 5 – Section 1
Physical Properties of Matter
Pages 134 - 138
Physical Properties of Matter
Remember, matter is defined as
anything that has mass and takes up
space.
Then what is a physical property of
matter?
A physical property is any
characteristic of matter that can be
observed without changing the identity
of the material.
Physical Properties
What are ways we can describe
matter using our 5 senses?
Qualitative Examples: Color,
Shape, Smell, Taste, States of
Matter.
Quantitative Examples: Mass,
Volume, Density.
Size Dependent Properties
A size dependent property is a
physical property that changes
when the size of an object changes.
Examples of size dependent
properties:
Length, Width, Height, Volume,
Mass.
Size Independent Properties
A size independent property is a
physical property that does not
change when the size of an
object changes.
Examples of size independent
properties:
Density, Color, State of Matter.
Mass
The mass of an object is the amount of
matter in an object.
The base metric units for mass are the gram
(g) and kilogram (kg).
Mass DOES NOT change, regardless of
location.
For Example: Your mass will be the same on
the moon as it is on Earth.
Mass is a size-dependent physical property.
Riddle
What weighs more,
more a pound
of bricks or a pound of
feathers?
Weight
Weight is a measure of the force of
gravity on an object.
Weight is measured in Newtons (N).
Weight DOES change depending on
the force of gravity.
For Example: Your weight will be
different on the Moon.
Mass vs. Weight (Examples)
On Earth: An Astronaut has a mass of
80 kg and a weight of 784 N.
On the Moon: The mass of the
Astronaut is the same (80 kg), but since
the gravity on the Moon is 1/6th that of
Earth, their weight is 130 N.
In outer space: The mass of the
astronaut is the same (80 kg), but since
there is zero gravity in outer space,
their weight is 0 N.
Volume
The volume of an object is the amount of
space that it takes up.
Volume is a size dependent physical
property.
For a liquid, volume is measured in liters (L)
or milliliters (mL).
For a solid, volume is measured in cubic
centimeters (cm3).
Remember, 1 mL = 1 cm3
Finding Volume of a Regular Shaped Object
Recall, that for a regular shaped object, volume can
be measured using the formula:
Step 1 (Formula): Volume = Length x Width x Height.
Step 2 (Substitute): Volume = 16 cm x 5 cm x 8 cm
Step 3 (Solve): Volume = 640 cm3
Finding Volume of an Irregular Shaped
Object
Cannot use this method to find the volume of
irregular shaped objects: rocks, shells, marbles,
etc.
For irregular shaped objects, the volume is
measured using water displacement.
Instruments used for measuring water
displacement include:
1) Graduated Cylinder
2) Overflow Can
Method #2: Graduated Cylinder
• Using a graduated cylinder:
1. Record initial volume of water in the graduated cylinder.
2. Place object GENTLY into cylinder.
3. Record the NEW volume of water.
4. Subtract Initial Volume from New Volume
5. Difference in volume is the volume of the object.
Volume of Object =
Ending Volume – Starting Volume
Example:
Volume = 23 mL – 20 mL = 3 mL
Method #2: Overflow Can &
Graduated Cylinder
• Using a graduated cylinder and Overflow Can:
1. Place the irregular shaped object into an overflow can.
2. Catch the liquid that overflows in a graduated cylinder.
3. The volume of the liquid that is in the overflow can is
equal to the volume of the object..
The volume of a solid object is measured in cm3, so if the
volume of liquid in the graduated cylinder is 40 mL, then
the volume of the solid object would be…
40 cm3……since mL = cm3
Riddle
What is more dense,
dense a pound
of bricks or a pound of
cotton balls?
Density
Density (D) is the amount of
mass in a given volume.
A golf ball is more dense than
a tennis ball.
The formula for density is:
Density = mass/volume or
D = m/v
Density
Some units for density are:
g/cm3 (solids)
g/mL (liquids)
g/cm3 = g/mL
Density is a size independent
property.
If you cut an object in half, then
density of the object would not
change.
Example Problem #1
Block of wood:
Mass = 100 grams
Volume = 25 cm3
What is the density of the block
of wood?
Density = Mass / Volume
Density = 100 grams / 25 cm3
Density = 4 g/cm3
Magic Triangle (Density)
Example Problem #2
The density of a marble is
2.0 g/cm3 and its mass is
10.0 g. What is its volume?
Volume = M / D
Volume = 10.0 g / 2.0
g/cm3
Volume = 5.0 cm3
Example Problem #3
After using water displacement,
you find that the density of a rock
is 0.8 g/mL and the volume is 21
mL. What is the mass of the rock?
Mass = Density * Volume
Mass = 0.8 g/mL * 21 mL
Mass = 16.8 grams
Density of Water
The density of water is:
1 g/mL or 1 g/cm3
For your information:
Objects > 1 g/mL (SINK)
Objects < 1 g/mL (FLOAT)