1. define heat and temperature
2. Differentiate between heat
and temperature at the
molecular level
Looking Back
The higher the frequency in the light
wave means greater energy
2. The longer the wavelength the greater
the energy
1.
Red color has the least amount of
energy
3.
Looking Back
4. Violet is the color that is bent the most
among the seven colors because it has
the longest wavelength.
5. Refraction is the bending of light rays
as they pass obliquely from one medium
to another.
Identify the following objects
Sun
What are these objects?
Sources of Heat
Candle
Fire
Kettle
Flat iron
Oven
Lamp
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Sources of Heat
Sun
Combustion
Friction
Electricity
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 is the transfer of thermal energy from
one object to another because of
temperature difference
 exists as “energy in transit” or in the
process of being transferred and it is
not contained in an object
 flow spontaneously from hot objects to
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cold objects
 the energy that is actually contained
in an object due to the motion of its
particles.
 depends on the mass, temperature
and phase ( solid, liquid or gas) of an
object
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Why do we need heat?
dry our clothes
keep us warm
cooking
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MEASURING HEAT
Heat
is measured by the units of calorie
and joule (J).
calorie: The amount of energy needed
to raise the temperature of 1 gram of
water by 1oC
1 calorie= 4.18 J
 the measure of the average kinetic
energy of all the particles in the object
due to their random motions through
space
 It indicates the degree of hotness or
coldness of a body or a place
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Temperature
is measured in
units called
degrees
(oC, oF, oK)
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Thermal expansion is where materials
expand while being heated,
causing them to take more space
All gases, liquids, and most solids
expand when their temperature increases.
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What happens when molecules move more?
More energy
Molecules move more
Molecules spread out
More energy
=
EXPANSION
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What happens when molecules move less?
Less energy
Molecules move less
Molecules get closer
together
Less energy
=
CONTRACTION
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What I Have Learned
I have learned that________________
I have discovered that________________
I have realized that________________
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What I Have Learned
I have learned that H_ _ _ _ is the transfer of
T_ _ R_ _ L E _ e_ _y from one object to
another
I have discovered that heat flows from
h_ _ body to c _ _ _ body
I have realized that heat and temperature
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are _____ the same
Directions: Choose the letter of the correct answer
1. Heat transfers from an area
of____temperature to an area of ___
temperature.
A. Low to high
B. Low to Low
C. High to low
D. High to high
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Directions: Choose the letter of the correct answer
2. Temperature of a body measures the
molecular_______.
A. average kinetic energy
B. average potential energy
C. differences in kinetic energy
D. differences in potential energy?
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Directions: Choose the letter of the correct answer
3. Heat is the transfer of _____ from one object
to another due to a difference in temperature.
A. Current
B. Energy
C. Force
D. Velocity
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Directions: Choose the letter of the correct answer
4. What happens to the molecules of a
substance as it gets cooler?
A.
B.
C.
D.
The molecules expand
The molecules move faster
The molecules move slower
The molecules shrink
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Directions: Choose the letter of the correct answer
5. What is the unit of heat?
A. Joule
B. Kilogram
C. Meter
D. Newton
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Answer
1.Heat transfers from an area of____temperature to an area of ___
temperature.
C. High to low
2. Temperature of a body measures the molecular_______.
A. average kinetic energy
3. Heat is the transfer of _____ from one object to another due to a difference
in temperature
B. Energy
4. What happens to the molecules of a substance as it gets cooler?
C. The molecules move slower
5. What is the unit of heat?
A. Joule
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Looking forward
1. Explain the effects of heat on a
body,( Phase Change)
2. Relate heat to mass and
temperature through the concept of
the specific heat capacity
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