Download Physical Science Chapter 2 Notes

Physical Science
Chapter 2 Notes
The Properties of Matter
Chapter 2 Overview
• Section 1: What is Matter?
– Matter has Volume and Mass
– Difference between Mass and
Weight
– Mass is a measure of Inertia
• Section 2: Describing Matter
– Physical and Chemical Properties
– Physical and Chemical Changes
Section 1: What is Matter?
• Matter = anything that has Volume &
Mass
• Volume is the amount of space taken up
• No 2 objects can occupy the same space
at the same time.
• Volume of a Liquid - Read at the Meniscus
• Volume of Solid
– Measure directly if rectangular sides
– If irregular sides, then can use displacement
– Relationship between mL and cm3
More on Matter
• Math Break p. 38
• Volume of Air
– The volume of air is simply the volume of the
container it is in
• Matter has Mass
• Mass is the amount of matter in a given
substance
• Mass does not change unless you remove or
add more matter to the object (p. 39)
Examples of Matter
Where does the mass of a
child come from as she grows?
• Does she have
mass and volume?
• Does her volume
and mass
increases as she
grows?
• Food adds both
space into matter
Mass and Weight Differences
• Mass is a measure of the
amount of matter in an objectbalance beam
• Weight is the measure of the
gravitational force on an
object. Depends on mass and
distance** p. 39 Figure 6.
• Weight measured with a spring
scale
MASS
• Amount of Matter
• Always constant
• Measured with
Balance
• Expressed in kg, g,
mg
WEIGHT
• A Measure of the
Gravitational Force
• Varies depends on
distance and mass
• Measured with
Spring Scale
• Expressed in
Newtons
Mass and Weight are Related
• Weight is pretty much constant on
Earth because gravity is constant on the
surface of the Earth
• Force = Mass times Acceleration
Mass is a Measure of Inertia
• Inertia is the tendency of all objects to
resist change in motion.
• Light objects easy to move
• Heavy objects not so easy to move
• P. 152: Momentum is a property of a
moving object that depends on the
objects mass and velocity. Faster and
heavier, harder to stop.
Measuring Matter
• Experimenting skills worksheet
• Read #1
• How could this be done?
Measuring matter
• Look at the charts on Tools of the trade.
• Fill in the type of tool that you would use to
measure each object or the measurement
for that tool in the chart.
Measuring matter
• In a graduated cylinder or beaker, most
liquids form a meniscus. This looks like an
arc or the liquid curves up at the edges
like a smile.
• Now do the problems…
Measuring Matter
•
•
•
•
Uncertainty in measurements….
This is possible. This can happen for many reasons.
Your lab equipment has error.
Yes, there is human error. You measured wrong…Read
the data wrong…Mixed the wrong ingredients or
chemicals…Did not accurately read at the
meniscus…etc.
• Your data you collected has to be as accurate as
possible, so many times you have to allow for error or
repeat your experiment again. Accuracy is the foundation
of science. If we were not accurate we could blow
ourselves up…..
• Lets read the scenario in uncertainty…
Section 2
Describing Matter
Describing Matter
• Matter can be described using
different properties.
• Describe these objects.
•Matter is described using Physical and
Chemical Properties
Physical Property
• Physical Properties can be observed
and measured without changing the
ID object
• Examples of Physical Properties (p.
44)
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–
–
–
–
–
Thermal Conductivity (transfer of heat)
State (solid, liquid, gas)
Malleability (ability to flatten)
Ductility (ability to be pulled into wires)
Solubility (ability to dissolve)
Density (mass per unit volume)
Density
• D=M/V
• Also can be described as amount
of matter per given volume
• Can use to identify substances
(like gold vs. pyrite)
• Math time
Chemical Property
• Ability to change into a new substance
• Examples of chemical Properties
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–
–
–
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flammability
Non-flammability
React with Oxygen
React with acid or base
React with water
Physical vs. Chemical Changes
• Physical changes are changes that
affects the physical properties of a
substance
– Example. Ice to Water, breaking a piece of
chalk, crumpling paper, sugar in lemonade
• Chemical changes occur when one or
more substances are changed into
entirely new substances.
– Examples. Burning paper, mixing acid with
chalk, oxidizing metal, souring of milk
Clues to Chemical Changes
• Physical changes can be reversed.
(ice-water)
• Chemical changes cannot be reversed.
• Clues for chemical changes include:
–
–
–
–
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color changes
visible reaction
smells
heat/light
gas bubbles