Heat and energy are related concepts in the field of thermodynamics, which is the science of the relationship between heat, work, temperature, and energy. Heat is the transfer of energy between systems or bodies due to their temperature difference. Thermal energy is the energy contained within a system that is responsible for its temperature. Heat is a form of energy in transit, while temperature is a measure of energy.

1. HEAT AND
TEMPERATURE
MR. ALVIN MARC M. DANCEL
SCIENCE TEACHER

2. SCIENCE 8- WEEK 6
LEARNING COMPETENCY:
The learner should be able to differentiate between
heat and temperature at the molecular level.

8. HEAT
 ENERGY in transit.
 It is transferred from one body to another as the
result of a difference in temperature. If two bodies
at different temperatures are brought together,
energy is transferred—i.e., heat flows—from the hotter
body to the colder. The effect of this transfer of energy
usually, but not always, is an increase in the
temperature of the colder body and a decrease in the
temperature of the hotter body.

9. HEAT
Heat naturally moves from an object with high
temperature to an object with low temperature.
 Objects do not contain heat; they contain
thermal energy. However, scientists prefer the
use of the term “internal energy” to refer to
thermal energy.
 Object with greater mass have more thermal
energy and can transfer more heat

10. TEMPERATURE
is the amount of energy present in an object due to
the motion of its particles or molecules.
 The greater the motion of the molecules of a body,
the greater is its temperature.
 Temperature can be directly attributed to the
molecules’ kinetic energy. Just like any moving
body, the molecules possess kinetic energy.

11. TEMPERATURE
 Temperature is the average kinetic energy of
the molecules of a substance.
 When an object absorbs or releases heat, the
following happens:
 Two or more of these changes can happen at
the same time.

12. TEMPERATURE
-measure of hotness or coldness expressed in terms of any of several
arbitrary scales and indicating the direction in which heat energy will
spontaneously flow.

13. TEMPERATURE CHANGE
When an object absorbs or takes in heat, the particles of
the object gain kinetic energy and move faster. As a result,
the TEMPERATURE INCREASES.

14. TEMPERATURE CHANGE
When an object releases or gives off heat, the particles of
the object lose kinetic energy and move slower. As a result,
the TEMPERATURE DECREASES

15. THERMAL EXPANSION
• Thermal expansion happens when the thermal (internal) energy
of a substance increases causing the particles to spread out
making the size of the object.
 When an object is heated (absorbs or takes in heat), it
expands.
 Expansion is the increase in size of a material.
 When an object is cooled (releases or takes off heat), it
contracts.

16. PHASE CHANGE
When an object absorbs or takes in heat or releases or gives off
heat, its phase also changes.

17. PHASE CHANGE
• When heat is absorbed, an object will undergo:
 Melting- phase change from solid to liquid
 Vaporization- phase change from liquid to gas
• Types of vaporization
a.Evaporation is the phase change that happens at the
surface of the liquid. Evaporation is a cooling process.
b.Boiling is the phase change that happens beneath the
surface of the liquid
 Sublimation- phase change from solid to gas

18. PHASE CHANGE
• When heat is released, an object will undergo
 Condensation- phase change from gas to liquid.
Condensation is a warming process.
 Freezing- phase change from liquid to solid.
 Deposition- phase change from gas to solid.

19. THANKS FOR
LISTENING!!!

20. Time (min) Temperature (°C)
0 (Initial) 5
2 9
4 14
6 19
8 22
10 24
12 27
14 29
Table 3: Temperature readings for melting ice
Q15. Why does the ice inside the container melt after sometime? (2 POINTS; PT)
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Q18. Describe the temperature of the water while the ice melting. (2 POINTS; PT)
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Q19. Describe the temperature of the water after the ice has melted. (2 POINTS; PT)

21.  HEAT VS TEMPERATURE
 Heat is a form of energy while temperature is not a form of energy.
Temperature is a measure of the average kinetic energy of the
particles and it does not depend on the mass of the object.
 * It can be measured directly with the use of thermometers. Heat
cannot be measured directly. But you can make use of the
measurable quantities related to heat to determine how much heat
(Q) is absorbed by the object.
 * These are the change in temperature (ΔT), mass (m), and specific
heat capacity (c) of the object. The relation among these quantities
is expressed as: Q = mc∆T

23. F.
• 1. Which has a higher temperature, 1 cup of boiling water or 1
teapot of boiling water? Which can transfer more heat, 1 cup
of boiling water or 1 teapot of boiling water? Explain your
answer (5 POINTS; WW).
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24. • I. Evaluating Learning
MULTIPLE CHOICE. Choose the letter of the correct answer. (10 POINTS; WW)
• _____1. A measure of the average kinetic energy of
the particles that make up a material
A) Temperature C) Heat
B) Thermal energy D) Specific heat

25. J. Additional activities for application or remediation.
Answer the following questions, briefly. Write your answer on the space provided. (10
POINTS; WW)
• 3. What direction does heat always flow? Give an
example.
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