Transcript Unit 6: Properties of Matter Ch 17: Properties of Matter

Unit 6: Properties of
Matter
Ch 17: Properties of Matter
• 17.1
• 17.2
• 17.3
• 17.4
Properties of Solids
Density of Fluids
Buoyancy of Fluids
Viscosity of Fluids
Chapter 17 Learning Goals
• Learn the definitions of terms used to
describe properties of matter.
• Learn how to calculate the density of solids.
• Learn how to find the density of liquids and
use your understanding to make a density
column.
• Use a density column to predict the density of
a solid.
• Investigate how the shape of an object can
determine whether it floats or sinks.
• Compare the weight of an object with the
weight of the water it displaces.
• Learn why certain fluids are more viscous
than others.
• Measure the viscosity of fluids using a
viscometer.
• Compare the properties of viscosity and the
Chapter 17 Vocabulary
Terms
•
•
•
•
•
brittleness
buoyancy
density
elasticity
hardness
• malleability
• tensile
strength
• viscosity
17.1 Properties of Solids
I. Chemical Properties
A. The way a substance reacts with
other substances to form new
substances with different
properties
B. Reactivity
1. the ability of a substance to
chemically combine with
another substance
2. ie – iron reacts with oxygen
to form rust
II. Physical Property
A. A characteristic of a substance
that be observed or measured
without changing the
composition of the substance
B. Many physical properties can be
observed using your five senses
C. Properties help us distinguish
between different types of matter
D. Properties of
Solids
1. density
2. hardness
3. elasticity
4. brittleness
5. malleability
6. tensile strength
7. Ability to
conduct
electricity
8. Ability to
conduct heat
Elasticity
Brittleness
E. Density
1. Formula
17.1 Properties of Solids
Key Question:
How can you find the
density of a solid?
2. Liquids tend to be less dense
than when in their solid form
3. Water is an exception.
a. Ice is less dense than liquid
water, so ice floats
b. Water molecules are more
tightly packed when in liquid
form
17.2 Density of Fluids
Key Question:
Can you create a
stack of fluids?
III. Chemical Changes
A. A change that occurs when a
substance changes composition
by forming one or more new
substances
B. Example
1. fruits and vegetables ripen –
chemical changes are occurring
2. browning of an apple
(bruising)
3. when food burns
IV. Physical Change
A. A change in the physical form or
properties of a substance that
occurs without a change in
composition
B. Examples
1. gasoline in your car changes
into a gas that is burned in the
car’s engine
2. Water is turned into steam to
heat homes and factories
3. Grinding peanuts into peanut
butter
4. Dissolving
5. Changes of state
a. melting
b. evaporating
c. sublimation
d. freezing
e. condensation
f. deposition
17.3 States of Matter
V. States of Matter
A. Buoyancy
1. a measure of
the upward
pressure a fluid
exerts on an
object
2. when a rock is
suspended in
air, it weighs
2.25 N
3. In water, it
weighs 1.8 N
B. Archimedes’ Principle
1. the force exerted on
an object in a liquid is
equal to the weight of
the fluid displaced by
the object
17.3 Buoyancy
• A solid cubic meter of steel
weighs 76,400 N.
• It displaces 9,800 N of water.
17.3 Buoyancy
• The same amount of steel, shaped
into a 10-cubic-meter boat, is
pushed under water.
• Now it displaces 98,000 N of
water.
17.3 Buoyancy
• When the boat floats, it displaces
76,400 N of water—which is equal
to the boat’s own weight.
C. Charles’ law
1. the volume of a gas
increases with
increasing temperature
2. the volume of a gas
shrinks with decreasing
temperature
3. Heated molecules
move with greater
energy
4. As the molecules
collide with each other,
they take up more
space
• The beach ball
and basketball
each contain the
same amount of
air.
• The basketball
has greater
pressure because
the air particles
are squeezed into
a smaller space
and collide with
the walls more
often.
D. Boyle’s Law
1. as the pressure of a gas
increases, its volume
decreases proportionately
2. as the pressure of a gas
decreases, its volume
increases proportionately
17.3 Volume vs.
Pressure
E. Bernoulli’s Principle
1. as a fluid (liquid or gas)
flows faster, the pressure it
exerts decreases
2. airplane wing design helps
give plane lift
http://home.earthlink.net/~mmc1919/venturi.html
F. Venturi Effect
1. as the velocity of a moving
fluid increases, the pressure
exerted by the fluid decreases
2. examples
a. water going down drain
b. garden hose
c. fuel into carburetor
G. Pascal’s Principle
1. pressure applied to a fluid is
transmitted equally throughout
the fluid
2. hydraulics
H. Sublimation
1. solid turns to gas without
going through the liquid phase
2. examples
a. freezer burn
b. dry ice
c. ice in freezer
d. clothes drying in winter
3. increases pressure causes
faster sublimation
I. Deposition
1. gas turns into solid without
going through liquid phase
2. snowflakes
J. Distillation
1. an impure liquid is heated to
its boiling point and turns into
gas – the gas then passes
through condenser and cools
into a liquid and is collected
2. used to purify liquids
K. Viscosity
1. resistance of a fluid to flow
2. as temperature increases,
- resistance decreases
- viscosity decreases
3. as temperature decreases,
- resistance increases
- viscosity increases
4. as pressure increases,
viscosity decreases