Transcript Energy Transfer and Transformations (7th Grade)

Big Idea 11:
Energy Transfer and Transformations
A. Waves involve a transfer of energy without a transfer of
matter.
B. Water and sound waves transfer energy through a
material.
C. Light waves can travel through a vacuum and through
matter.
D. The Law of Conservation of Energy: energy is conserved
as it transfers from one object to another and from one form
to another.
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SC.7.P.11.1
Recognize that adding heat to or removing heat from a
system may result in a temperature change and possibly a
change of state.
SC.7.P.11.2
Investigate and describe the transformation of energy from
one form to another.
SC.7.P.11.3
Cite evidence to explain that energy cannot be created nor
destroyed, only changed from one form to another.
SC.7.P.11.4
Observe and describe that heat flows in predictable ways,
moving from warmer objects to cooler ones until they
reach the same temperature.
Benchmark Number & Descriptor
Measure of kinetic
energy of
molecules
 Measured with a
thermometer
 3 Scales
◦ Fahrenheit
◦ Celsius
◦ Kelvin
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F = Fahrenheit (used for
weather)
◦ Water boils at 212°F.
◦ Water freezes at 323° F.
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C = Celsius (used in
science)
◦ Water boils at 100°C.
◦ Water freezes at 0°C.
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K = Kelvin
(used in science)
◦ Only scale that has absolute
zero
 Particles are said to have no
movement at this temp.
Temperature
◦ The total energy of
the particles in a
material
◦ Depends on
temperature, mass,
and type of substance
A
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80ºC
Which beaker of
water has more
thermal energy?
◦ B - same
temperature, more
mass
B
80ºC
400 mL
200 mL
Thermal Energy

HEAT is the transfer of energy from one
object to another when the two things are at
different temperatures and in some kind of
contact.
◦ Always transfers from hot to cold

Ex: Teapot heats on stove top
cup of tea cools down (loses energy as
heat)
HEAT
Heat Transfer
 Heat
is always
transferred from
hot to cold.
 Heat
is
transferred by
conduction,
convection, and
radiation.
1.
____ is a measure of how quickly atoms are
moving.
2.
A ____ measures the temperature of
matter.
3.
The total amount of ____in an object is
known as thermal energy.
4.
Which object has more thermal energy: Cup
of coffee at 80°F or a bathtub filled with
coffee at 60°F?
KNOWLEDGE CHECK
1.
TEMPERATURE is a measure of how quickly atoms
are moving.
2.
A THERMOMETER measures the temperature of
matter.
3.
The total amount of KINETIC ENERGY in an object
is known as thermal energy.
4.
Which object has more thermal energy: Cup of
coffee at 80°F or a bathtub filled with coffee at
60°F?BATHTUB = more particles, more energy
KNOWLEDGE CHECK
TRANSFER of
ENERGY
Thermal energy is always moving all
around you.
 Thermal energy affects your life in very
important ways.
 Changes in weather, cooking your food,
and heating your house are a few of the
ways the transfer of thermal energy helps
us.
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TRANSFER OF THERMAL
ENERGY
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The transfer of
heat by direct
contact between
objects or
particles

Heat transferred
by the movement
of molecules
within a
substance

Movement occurs
from warmer
areas to cooler
areas
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Heat transferred
through space in
the form of waves
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EXAMPLE: The
sun’s rays causing
a sunburn
CONDUCTOR
INSULATOR
Conductors are
 An insulator is a
materials that
material that does
transfer heat
not transfer heat
easily.
easily.
 Examples:
 Examples:
◦ liquids and gases
◦ metals like
◦ jacket
copper and gold
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Helping or Slowing the Flow of
Energy
1.
What examples of
thermal energy and
thermal energy transfer
can you see around you
right now?
KNOWLEDGE CHECK
1.
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What examples of thermal
energy and thermal
energy transfer can you
see around you right now?
Microwave, sun = radiation
Stove/pan, spoon in heated
pot = conduction
Air currents = convection
KNOWLEDGE CHECK
MATTER and HEAT
States of Matter
SOLID = particles are
close together, move
slow (vibration)
 LIQUID = particles
spread apart, slide past
each other
 GAS = particles move
fastest, move
everywhere (spread
out)
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Energy and Matter
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Solid = least amount
of energy
Liquid = medium
energy
Gas = most energy
Energy is related to
particle movement.
MATTER and HEAT
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Phase changes
occur when an
objects state of
matter change.
In order for a
change in phase
to occur, energy
must be either
released or
absorbed.
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Solid -> Liquid
◦ Melting
◦ Energy is absorbed.
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Liquid -> Solid
◦ Freezing
◦ Energy is released.
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Liquid -> Gas
◦ Vaporization
◦ Energy is absorbed.
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Gas -> Liquid
◦ Condensation
◦ Energy is released.
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Solid -> Gas
◦ Sublimation
◦ Energy is absorbed.
PHASE CHANGE and ENERGY
1.
2.
3.
4.
Identify whether energy
needs to be absorbed or
released in the following
scenarios:
Ice cube melting
Boiling water
Dry ice placed in the air
Dew forming on grass
KNOWLEDGE CHECK
Identify whether energy needs
to be absorbed or released in
the following scenarios:
1. Ice cube melting Released
2. Boiling water Absorbed
3. Dry Ice placed in the air
Absorbed
4. Dew forming on grass Released
KNOWLEDGE CHECK