It’s
Hot
In
Here
It’s Hot in Here
Overview
Within this learning cycle, students explore temperature and heat. Within cooperative
groups, students explore temperature changes, and energy transfer. Measurement,
observations, inquiry, and alternate assessments provide the basis for development of
various concepts.
National Science Education Standards:
As a result of activities in grades K-4, all students should develop
Content Standard A: Science as Inquiry
Abilities necessary to do scientific inquiry - asking simple questions about objects,
organisms and events in the environment, plan and conduct investigations using simple
equipment and tools to collect data and extend senses, use data to give an explanation to
observations, and communicate their ideas and results to others.
Content Standard B: Physical Science
Give students a chance to increase their understanding of the characteristics of
objects and materials that they encounter daily. Through the observation, manipulation, and
inquiry students will be able to determine that heat can be produced in many ways, such as
burning, rubbing, or mixing one substance with another. Heat can move from one object to
another by conduction.
Louisiana Benchmarks/GLE#:
Physical Science
3rd Grade
20. Measure temperature by using Fahrenheit and Celsius thermometers and compare
results
28. Describe the reflection/absorption properties of various colored objects
29. Determine which materials insulate best by using experimental data
4th Grade
33. Describe how heat energy moves through a material by conduction
Hot Vs. Cold
Exploring why measuring temperature is important
Getting Started:
1. Determine objectives for lesson
2. Gather materials
3. Copy student Handouts
Materials: per group
Thermometers
Three bowls
Cold water
Warm water
Room temperature water
Procedure:
1. Form cooperative groups, give the students the three different bowls.
2. Instruct students to following the directions and write down their
observations.
3. Write on the board their observations.
4. Let each group take the temperature of each bowl
5. Write the temperatures on the board.
6. Discuss the importance of taking temperature readings instead of relying
on observations only.
7. Alternative assessment: Temperature cartoon
Safety Notes:
Make sure the warm water is not too hot for the students. Teach students
proper techniques for handling warm water and thermometers.
Hot Vs. Cold
(Student Sheet)
A. Hot and Cold
1. Place one finger into the bowl labeled Hot and a another finger
from your other hand into the bowl labeled Cold for 30
seconds.
2. After the 30 seconds, remove fingers and place both of them into
the room temperature bowl.
Observations:
Write what you felt as you moved your finger from the hot bowl to
the room temperature bowl.
Write what you felt as you moved your finger form the cold bowl to
the room temperature bowl.
B. Temperature
1. Measure the temperature of the water in each of the three
bowls.
2. Record the temperatures in your journal.
Hot Vs. Cold
(Student Sheet)
Read the cartoon and fill in the answer that belongs in the box on
the last frame.
Radiation: Energy Transfer
Exploring heat transfer through inquiry
Getting Started:
1. Determine objectives to be taught and the level of your students.
2. Design experiments for the students to conduct based on the objectives
to be taught.
3. Decide if each group will perform a different experiment or the same
experiment
4. Gather materials needed
5. Copy student handouts
Materials:
vary depending on experiments to be performed
Various cups/ containers- conductors and insulators
(Aluminum cans, Styrofoam, glass, plastic, etc)
Different colored paper or cloth
(can use black and white only to prevent confusion)
Different types of liquids
Thermometers
Ice
Water
Graduated cylinders
Heat source (heat lamps or the sun)
Banner paper
Markers
Procedure:
1. Give groups a problem to test.
2. Groups will perform desired task (choosing variables, designing
experiment, etc)
3. Students conduct experiment.
4. Each group presents their results to the class.
5. Discussion of concepts to follow presentations.
Safety Notes:
Make sure students follow lab safety with hot objects. Proper techniques when
using thermometers should be reviewed with students. Do not allow students
to heat any flammable liquids.
Teacher notes:
The level of your students will depend on whether you will write the procedure
for them to follow or allow them to design their own experiment.
Energy Transfer by Radiation
(Student Sheet)
Each group will be testing a different question. Design an
experiment, collect data and draw conclusions. Place all
work into your journal.
Problem:
state the question you want to answer
Independent Variable:
Dependent Variable:
Constant Variables:
Materials: List all the materials you will need to test your question. If material is not
here that you will like to use- ask.
Hypothesis:
Procedure: Write a detailed procedure of how you will test your question.
Results:
Draw a data table to collect data and graph once data is collected.
Conclusion: State a summary of your results.
Explain what you would do differently to
improve your experiment.
Reflection:
What did you learn? How could you do this experiment in your classroom.
Problems to be Tested
Problem: Which colors will absorb more Energy from the
sun?
Problem: Which materials will absorb more Energy from the
sun?
Problem: How does the amount of matter present change
the amount of energy absorbed?
Problem: Which type of container will keep water the
coldest?
Problem: Do different liquids change temperature the same?
Problem: Which temperature of water will heat up faster?
Conduction of Heat
Explore the process of conduction
Getting Started:
1. Cut metal coat hangers into strips of metal.
2. Melt birthday candle wax on metal rods few centimeters apart along the
metal rod.
3. Gather materials.
4. Copy student handouts.
Materials: per group
Metal rod
Candle
Clay to hold candle upright
Matches
Cloth Towels (hold the end of metal rod)
Procedure:
1. Form cooperative groups.
2. Explain the purpose of the investigation and show students how to
perform the task.
3. Let the students perform the task writing observations in their journal
notebook.
4. Discussion of students’ observations.
Safety Notes:
Students should wear safety goggles when dealing with an open flame. Make
sure the students have an oven mitt or cloth towel to hold the end of the metal
rod to prevent burning of hands. You may need to light the candle for each
group for safety.
Teacher Notes:
Make sure that the candle wax that is placed on the metal rods is a color that is
easily visible. Also make sure the candle wax dots are not too thick. This
activity can also be performed as a demonstration.
Conduction of Heat
(Student Sheet)
Purpose: To observe the transfer of heat by conduction.
Materials: goggles, candle, oven mitten, and metal rod
Hypothesis: State which order you think the wax will melt.
Procedure:
1. Light a candle.
2. Using an oven mitten, hold the tip of the metal rod in the candle flame.
Observations:
What happened to the wax?
What order did the wax melt?
Questions:
Why is the wax melting?
In what direction is the heat moving?
What is the heat moving through?
Conclusion:
I think metal is a good conductor of heat because_______________.
Convection
Overview:
This activity is a good way to visualize the process of convection. It is also a
good review of particle movement changes with temperature changes as well
as earth science integration.
Getting Started:
1. Determine objectives to be taught.
2. Gather materials.
3. Copy student handouts.
Materials: per group
Two glass jars of the same type (mouth of bottles must match)
2 colors of Food coloring (red/yellow or blue/yellow work well)
Water
Method of heating water
2 Playing cards
Oven Mitt
Procedure:
1.
2.
3.
4.
Form cooperative groups.
Show students the task you would like them to perform.
Make sure students record their observations in their journal notebooks.
Discuss the student observations.
Safety Notes:
Make sure the hot water is not too hot to prevent burns. If students are to
manipulate the jars make sure they wear oven mitts or use towels to handle
the jars.
Convection
(Student Sheet)
Following the directions below and write your observations in your journal.
Motion of Molecules
1. Fill one glass jar ¾ full with cold water.
2. Place two or three drops of the yellow food coloring into this jar.
Make observations: What is the food coloring doing in the water?
3. Fill a second jar ¾ full with warm water.
2. Place two or three drops of the red or blue food coloring into this jar.
Make observations: What is the food coloring doing in the water?
Which food coloring is spreading the fastest?
I know the ____________ water molecules are moving faster because __________________.
Convection Currents
1. Fill the cold water bottle with cold water to the top.
2. Fill the warm water bottle with warm water to the top.
Cold Over Hot:
3. Place a playing card or index card over the mouth of the cold water bottle.
4. Hold the card in place as you turn the bottle upside down and rest it on the top of
the warm water bottle.
* The bottles should be positioned so that they are mouth to mouth, and the card is
separating the two liquids.
5. Carefully slip the card out from in between the two bottles. Make sure that you are
holding onto the top bottle when you remove the card.
Make observations: Carefully watch what happens in the middle of the two bottles
and what is happening to the colors.
Hot over Cold:
1. Refill bottles and place food coloring as you did in part A of this activity.
2. Repeat steps 1-5 from part B; this time place the bottle of cold water on top of the warm
water.
Make observation: Carefully watch what happens to the colors.
Background information
You probably put on a sweater or a jacket when it’s cold outside. Like wise, you
probably wear shorts in the summer when it gets hot. But how hot is hot, and how
cold is cold? The terms hot and cold are not scientific terms. If you really want to
specify how hot or cold something is, you must use temperature.
Temperature is a measurement of the average kinetic energy of the particles in an
object. It can also be described as the combined movement of the particles in an
object. All matter is made of particles- atoms or molecules- that are in constant
motion. Because the particles are in motion, they have kinetic energy. The faster the
particles are moving, the more kinetic energy they have. Therefore, the higher the
temperature of the object the more kinetic energy the particles of an object have.
High Temperature
Low Temperature
Many thermometers are a thin glass tube filled with a liquid. Mercury and alcohol are
often used in thermometers because they remain liquids over a large temperature
range. Thermometers can measure temperature because of thermal exp0ansion.
Thermal expansion is the increase in volume of a substance due to an increase in
temperature. As a substance gets hotter, its particles move faster. The particles
themselves do not expand, they just spread out so that the entire substance expands.
Different substances expand by different amounts for a given temperature change.
When you insert a thermometer into a hot substance, the liquid inside the
thermometer expands and rises.
Temperature can be expressed according to different scales. Notice how the same
temperatures have different readings on the three temperature scales shown below.
When you hear a weather report that gives the current temperature as 70 0, chances
are that you are given the temperature in degrees Fahrenheit (0F). In science, the
Celsius scale is used more often than the Fahrenheit scale. The Celsius scale is
divided into 100 equal parts, called degrees Celsius (0C), between the freezing point
and boiling point of water. A third scale, called the Kelvin (or absolute) scale, is the
official SI temperature scale. The Kelvin scale is divided into units called kelvins (k)not degrees kelvin. The lowest temperature on the Kelvin scale is 0 K, which is
called absolute zero. It is not possible to reach a temperature lower than absolute
zero. In fact, temperatures within a few billionths of a Kelvin above absolute zero
have been achieved in laboratories, but absolute zero itself has never been reached.
Temperature Conversions
A given temperature is represented by different numbers on the three temperature
scales. You can convert from one scale to another using the simple equations shown
below.
To Convert
Equation
oC to oF
oF = (9/5 x oC) + 32
oF to oC
oC = 5/9 x (oF – 32)
oC to K
K = oC + 273
o
oC = K - 273
K to C
Example
= (9/5 x 45 oC) + 32
o
20 C = 5/9 x (68oF – 32)
318K = 45oC + 273
-241oC = 32K - 273
113oF
What is Heat?
You might think of the word heat as having to do with things that feel hot. But heat
also has to do with things that feel cold. In fact, heat is what causes objects to fell hot
or cold or the get hot or cold under the right conditions. Heat is the transfer of energy
between objects that are at different temperatures.
Why do some things feel hot, while others feel cold? When two objects at different
temperatures come in contact, energy is always transferred from the object with the
higher temperature to the object with the lower temperature. When ice melts into
your hand, heat from your body is transferred to the ice which makes your hand feel
cold.
Heat and Thermal Energy
If heat is a transfer of energy, what form of energy is being transferred? The answer
is thermal energy. Thermal energy is the total energy of the particles that make up a
substance. Thermal energy, is expressed in joules (J), depends partly on
temperature. An object at a high temperature has more thermal energy than it would
at a lower temperature. Thermal energy also depends on how much of a substance
you have. The more moving particles there are in a substance at a given
temperature, the greater the thermal energy of the substance.
When you hold an ice cube, thermal energy is transferred from your hand to the ice
cube. The ice cube’s thermal energy increases, and it starts to melt. But your hand’s
thermal energy decreases. The particles in the surface of your skin move more
slowly and the surface temperature of your skin drops slightly. So your hand feels
cold.
Reaching the same Temperature
When objects at different temperatures come in contact, energy will always be
transferred from the higher-temperature object to the lower-temperature. This point is
called thermal equilibrium. When objects are at thermal equilibrium, no net change in
either object’s thermal energy occurs. Although one object may have more thermal
energy, both objects have the same temperature.
Energy transfer processes
There are three processes involving energy transfer: conduction, convection, and
radiation.
Conduction
Imagine that you put a cold metal spoon in a bowl of hot soup. Soon the handle of
the spoon warms up- even though it is not in the soup? The entire spoon gets warm
because of conduction. Conduction is the transfer of thermal energy from one
substance to another through direct contact. Conduction can also occur within a
substance, such as the spoon.
As substances come in contact, particles collide and thermal energy is transferred
from the higher temperature substance to the lower temperature substance.
Remember that particles of substances at different temperatures have different
average kinetic energy. So when particles collide, higher kinetic energy particles
transfer kinetic energy to lower kinetic energy particles. This makes some particles
slow down and other particles speed up until all particles have the same average
kinetic energy. As a result , the substances have the same temperature.
Conduction and insulators
Substances that conduct thermal energy very well are called conductors. Energy is
transferred rapidly from a higher temperature to a lower temperature. Substances
that do not conduct thermal energy very well are called insulators. Energy is
transferred very slowly. Below is a chart of examples of conductors and insulators.
Conductors Insulators
Metal
cloth
water
rubber
Plastic
cork
Air
Styrofoam
Ceramic
Convection
When you boil a pot of water, water moves in roughly circular patterns because of
convection. Convection is the transfer of thermal energy by the movement of a
liquid or a gas. The water at the bottom of a pot on a stove burner gets hot because
of contact with the pot itself (conduction). As a result, the hot water becomes less
dense because its higher energy particles have spread apart. The warmer water
rises through the denser, cooler water above it. At the surface, the warm water
begins to cool, and the lower energy particles move closer together, making the water
denser. The denser, cooler water sinks back to the bottom, where it will be heated
again. This circular motion of liquids or gases due to density differences that result
from temperature differences is called a convection current.
Radiation
Unlike conduction and convection, radiation can involve either an energy transfer
between particles of matter or an energy transfer across empty space. Radiation is
the transfer of energy through matter or space as electromagnetic waves, such as
visible light and infrared waves. All objects radiate electromagnetic waves. The sun
emits mostly visible light, which you can see and your body can absorb, making you
feel warmer.
Heat and Temperature Change
Different substances have different thermal conductivities. Thermal conductivity is
the rate at which a substance conducts thermal energy. Conductors, such as a
metal, have a higher thermal conductivity than do insulators such as cloth. Because
of the metal’s higher thermal conductivity, it transfers energy more rapidly to your
hand when you touch it than the cloth does. Even when the cloth and metal are the
same temperature, the metal feels hotter.
Another difference between the metal and the cloth is how easily they change
temperature when they absorb or lose energy. When equal amounts of energy are
transferred to and from equal masses of different substances the change in
temperature for each substance will differ. Specific heat capacity is the amount of
energy needed to change the temperature of 1 kg of a substance by 1 oC. Different
substances have different specific heat capacities.
Differences between Temperature, Thermal Energy, and
Heat
Temperature
A measure of the average
kinetic energy of the
particles in a substance
Expressed in degrees
Fahrenheit, degrees
Celsius, or kelvins
Does not vary with the
mass of a substance
Thermal Energy
The total energy of
the particles in a
substance
Expressed in Joules
Heat
The transfer of energy
between objects that are at
different temperatures
Amount of energy transferred
expressed in joules or calories
Varies with the mass
and temperature of a
substance
Varies with the mass, specific
heat capacity, and
temperature change of a
substance