Table of Contents
STAGE 2 - SCIENCE (HEAT) TERM ONE 2016
Curriculum Source:
- WPS: Teaching context proposed by WPS teachers: 'All fired up' (or something)?
Outcomes:
- ST2-12MW Students identify that adding or removing heat causes a change of state between solids and liquids.
- ST2-13MW Students identify the physical properties of natural and processed materials, and how these properties influence their use.
BOS: Content:
1. A change of state between solid and liquid can be caused by adding or removing heat. (ACSSU046)
- STUDENTS: describe some everyday situations where solids and liquids change state by adding heat (heating) or removing heat (cooling)
- CRITICAL & CREATIVE THINKING: predict and observe the effects of adding heat or removing heat on a variety of everyday solids and/or liquids, eg butter, chocolate and water CCT
- describe how scientific knowledge about the effects of heating and cooling is used by people in their everyday life, eg the types of clothes worn, the packaging and preparation of food and everyday devices, eg freezers, irons or cooktops
2. Natural and processed materials have a range of physical properties which influence their use. (ACSSU074)
- STUDENTS: observe the changes that occur in the physical properties of everyday materials when they are heated, cooled, bent, stretched, folded and twisted
- LITERACY: observe and describe the structure of materials that can be seen with the naked eye and a magnifying glass, eg grains in bread, particles in chipboard or cork, threads within a fabric or fibres in paper
- identify the properties of some natural and processed materials
- describe how a range of common natural and processed materials are used in everyday life
- CRITICAL & CREATIVE THINKING: generate ideas about how the physical properties of some natural and processed materials influence their use.
Example Introduction:
When something feels hot, the molecules in that 'something' are moving very fast. When something feels cool, the molecules in that object aren’t moving quite so fast.
For example, when we are cold, we can jump up and down to get warmer. To help cool down, we can stay very still.
The human body has a variety of ways (senses) to detect energy.
- Your eyes perceive certain frequencies of electromagnetic waves as light.
- Your ears perceive certain frequencies of longitudinal waves as sound.
- Your skin, mouth and tongue can perceive thermal energy as hot or cold.
The amazing thing is that the human body detects how fast molecules are moving by how hot or cold something feels.
What a magnificent energy sensing instrument the human body is!
- Source What is heat? (Caltech)
- Source: Heat & Temperature
- Source: Jiggling|Heat & Jiggling
I will be using on-line simulation software for some experiments because using hot things in the classroom can be a risky business.
My STEAM Heat Project will Identify. Explore and Discuss...
- Describe some everyday situations where solids and liquids change state by adding heat (heating) or removing heat (cooling)
- Predict and observe the effects of adding heat or removing heat on a variety of everyday solids and/or liquids, eg butter, chocolate and water CCT
- Describe how scientific knowledge about the effects of heating and cooling is used by people in their everyday life, eg the types of clothes worn, the packaging and preparation of food and everyday devices, eg freezers, irons or cooktops
- Observe and record the changes that occur in the physical properties of everyday materials when they are heated, cooled, bent, stretched, folded and twisted
- Observe and describe the structure of materials that can be seen with the naked eye, a magnifying glass and other technologies
- Identify the properties of some natural and processed materials
- Describe how a range of common natural and processed materials are used in everyday life
- Generate ideas about how the physical properties of some natural and processed materials influence their use.
Example Visual Design Element (Image/Video):
Video 1. How the human body senses hot and cold
- IF UNABLE TO ACCESS YOUTUBE VIDEO (requires Flash) TRY:How the human body senses hot and cold
Example Procedure:
- I made a guess about what makes things feel hot or cold (my hypothesis),
- I described how scientific knowledge about the effects of heating and cooling is used by people in their everyday life
- I identified that adding or removing heat causes a change of state between solids and liquids.
- I observed the changes that occur in the physical properties of everyday materials when they are heated, cooled, bent, stretched, folded and twisted
- I observed the structure of materials that can be seen with the naked eye and a magnifying glass, eg grains in bread, particles in chipboard or cork, threads within a fabric or fibres in paper
- I identified the physical properties of natural materials, and how these properties influence their use.
- I identified the physical properties of processed materials, and how these properties influence their use.
- I generated ideas about how the physical properties of some natural and processed materials influence their use.
- Used evidence (data) that I had collected to help see if my guess (hypothesis) was correct.
- Included visual design/artistic elements to improve reader understanding and interest.
Example Experiments: How Heat (Jiggling) Causes Molecules To Move
The purpose of this simple experiment is for students to determine the relationship between temperature and speed of molecules in a liquid.
Students will use water & food dye to discover more about 'jiggling' and heat: Source: http://www.coffeecupsandcrayons.com/simple-heat-experiment/
Fig 1. Heat experiment - Food colouring
| Instructions | Results |
|---|---|
| Do molecules move faster or slower when they are warmer? | |
| Which of the three jars spreads the food colour fastest | |
| Which of the three jars spreads the food colour slowest |
Molecules move faster when they are warmer and slower when they are colder. The drop of food colouring spreads out fastest in the hot water because the molecules are moving the fastest of the three jars. The food coloring spreads out fairly quickly in room temperature water and slowest in the cold water. Eventually the food coloring spreads throughout all three jars.
During the food colour experiment - you may notice condensation: https://www.youtube.com/watch?v=_QH52gQy0Ac http://viewpure.com/_QH52gQy0Ac
Example Experiments - Heat from Rubbing:
Explain the importance and consequences of heat produced by rubbing things together.
1. Rubbing your hands to make them warm:
| Instructions | Results |
|---|---|
| Rub the palms of the hands together slowly and then quickly. What do you notice? |
Students should find that hands get hot: even hotter when rubbed together quickly.
2. Put two identical coins on a rug or on a table cloth:
- First, place one finger on a coin and rub the coins forwards and backwards on the carpet.
^Instructions ^ Results^
| Place a finger on each coin. Which coin seems hotter |
Students should find that the coin that was rubbed on the cloth/carpet feels hotter.
3. Think of examples of rubbing things causing heat, e.g. tires on the road, making a fire with a bow, water-skiing with bare feet
| Enter your own examples here: | |
|---|---|
| 1 | |
| 2 | |
| 3 |
The experiments should show that:
- Things heat up when they are rubbed together.
- Rubbing things that feel rough get hotter than rubbing things that feel smooth.
Interactive 1. Changing State - Liquid, Solid and Gas
Example Classroom Experiment
Students will investigate state and temperature changes by creating Heat Sensitive Worms using Sodium alginate polymers. It immediately changes from a liquid to a solid the moment it touches the Worm Activator solution.
The worms change color due to the special thermochromic dye in the Heat Sensitive Worm Goo. Thermochromic means that a color change (chromic) occurs in accordance with temperature (thermo) of the worm goo.
The sodium alginate (Worm Goo) and activator is a safe, low cost chemical used as a thickening agent in fruit pies and ice-cream. Calcium (chalk) is used as an activator. Food-grade alginate and calcium can be purchased locally, easily and cheaply.
Example - State Table (BBC interactive experiments & results):
In your class/group discussions, describe some everyday situations where solids and liquids change state by adding heat (heating) or removing heat (cooling)
Complete the on-line interactive tasks to predict, observe and record the effects of adding heat or removing heat on a variety of everyday solids and/or liquids, eg butter, chocolate and water
1. Drag chocolate into the glass beaker and then press buttons to heat, cool and test:
| Follow the instructions: | Enter your answer below: |
|---|---|
| 1. When you press the 'heat' button, what happens to the chocolate? | |
| 2. What temperature is the chocolate now? | |
| 3. When you press 'test' to wobble beaker. Does chocolate move like solid or liquid now? | |
| 4. Press 'cool' then 'test' to wobble beaker. Does chocolate move like solid or liquid now? | |
| 5. What temperature is the chocolate now? |
2. Drag candle wax into the glass beaker and then press buttons to heat, cool and test:
| Follow the instructions: | Enter your answer below: |
|---|---|
| 1. When press you press the 'heat' button, what happens to the candle wax? | |
| 2. What temperature is the candle wax now? | |
| 3. When you 'test' to wobble beaker. Does wax move like solid or liquid now? | |
| 4. Press 'cool' then 'test' to wobble beaker. Does wax move like solid or liquid now? | |
| 5. What temperature is the candle wax now? |
3. Drag aluminium can into the glass beaker and then press buttons to heat, cool and test:
| Follow the instructions: | Enter your answer below: |
|---|---|
| 1. When press you press the 'heat' button, what happens to the aluminium can ? | |
| 2. What temperature is the aluminium can now? | |
| 3. When you press 'test' to wobble the beaker. Does can move like solid or liquid now? | |
| 4. Press 'cool' then 'test' to wobble beaker. Does can move like solid or liquid now? | |
| 5. What temperature is the aluminium can now? |
4. Drag butter into the glass beaker and then press buttons to heat, cool and test:
| Follow the instructions: | Enter your answer below: |
|---|---|
| 1. When press you press the 'heat' button, what happens to the butter? | |
| 2. What temperature is the butter now? | |
| 3. When you press 'test' to wobble beaker. Does butter move like solid or liquid now? | |
| 4. Press 'cool' then 'test' to wobble beaker. Does butter move like solid or liquid now? | |
| 5. What temperature is the butter now? |
5. Drag lime lolly into the glass beaker and then press buttons to heat, cool and test:
| Follow the instructions: | Enter your answer below: |
|---|---|
| 1. When press you press the 'heat' button, what happens to the lime lolly? | |
| 2. What temperature is the lime lolly now? | |
| 3. When you press 'test' to wobble beaker. Does lime lolly move like solid or liquid now? | |
| 5. What temperature is the lime lolly now? |
References and optional additional activities:
- Heating chocolate: http://www.bbc.co.uk/schools/scienceclips/ages/8_9/solid_liquids.shtml
Example Observations:
Students will observe, describe and compare materials using the naked eye and one or more instruments such as a 'thermographic' (infrared) webcam, microscope or similar.
A thermographic camera (also called an infrared camera or thermal imaging camera) is a device that forms an image using infrared radiation compared with a standard webcam/camera, which forms an image using visible light.
Figure 1. Thermographic Images - Show how a ball heats up after being bounced - Source: Caltech
You may think these infrared images of a boy holding a ball look unusual, but this is the way snakes normally see things!
CSI Wahroonga - Investigating Properties of Natural & Processed Materials:
To observe and identify properties of some natural and processed materials.
Cheap infrared cameras can also be used to observe materials in ways that cannot be seen using visible light (see images on right).
Place a playing card into an envelope (suggest a spade or club suit which is easily identifiable - a three of spades for example). Before sealing the envelope, make sure that the value of the card cannot be read in visible light but that the value is visible when held in front of an infrared webcam (X-Ray vision using infrared webcam). Choose a different envelope if necessary. This worked well in tests using a red birthday card envelope and a simple brown paper envelope. The image at right shows a playing card in an envelope when viewed via standard versus infrared webcam:
The only difference between the above images is that the image on the right was taken using a $10 infrared sensitive webcam.
These are actual images of the cards in the envelope (above) - No changes, tricks or editing
Set up one or more infrared webcams that students may use. Students are told that there are a number of items concealed in envelopes. They must use a scientific instrument to find a way to identify the items without opening the envelope. The teacher may provide hints but ideally leave it to the students to discover a solution. Students record their results in a table:
Example Infrared Investigation:
| Colour of envelope. | Describe the hidden item in the envelope |
|---|---|
| Red | Playing card - eight of spades |
| White | Drawing of a cat |
See WPS WIKI: Infrared Page for lots more ideas about investigating heat using infrared and other properties of light
Video 2. How snakes see using hot and cold (infrared)
- IF UNABLE TO ACCESS YOUTUBE VIDEO (requires Flash) TRY:How snakes see using hot and cold (infrared)
Have the above experiments changed the way you think about heat?
Example Research & Data Collection:
- I visited museums and/or sites on the Internet like
- I found out about the modern science of heat compared with old/traditional ideas about heat.
using Google sheets or similar).
- I asked people to fill in 'My Keep Cool Survey', including their age and occupation, to find out what people think about what makes things hot or cold.
- I perfomed experiments then analysed and discussed the results.
- I created a survey (data organised in rows + columns on a sheet of paper or an on-line survey
- I used a maths formula/software that I found on the Internet to compare/graph my results.
Example - Physical Properties Of Natural & Processed Materials:
Scientific knowledge about the effects of heating and cooling is used by people in their everyday life, eg the types of clothes worn, the packaging and preparation of food and everyday devices, eg freezers, irons or cooktops.
Create a simple survey to find out what people think about the properties of materials that make those materials feel hot or cold to touch.
| Student or Adult | Is Metal warmer, colder or same as wood | Does the fridge light go out when door closed? |
|---|---|---|
| Student | Colder | No |
| Adult | Hotter | Yes |
| Student | Hotter | No |
| Adult | Same | Yes |
| Student | Colder | Yes |
Table 2. Example - Properties Of Materials Survey:
Discuss the results of your 'Properties of Materials Survey' results in the section below.
My results for Table 1 (above) show that most adults and students (66%) think that metal is colder than wood. This confirms the misconceptions that most people may have (as described in Video 1. above).
*All data from Table 1 was evaluated and graphed using Google Sheets formulas.
Example Discussion:
Data in Table 1: Most of the ideas about heat/cold fall into three main types:
- Motion
- Temperature
- Change of state
My favourite experiment was the worms because it was easy to see what caused the worms to change colour and to change state
In my survey 80% of people think that being 'hot' or cold is a property of a material: They think that metal objects are cold and polystyrene and wood are warm when both materials are measured as being at exactly the same temperature.
Similarly temperature is not a measure of the heat content of a body. Instead, Heat is energy. Temperature is how hot or cold a body is - related to the energy of the particles within the body.
My survey results confirmed the findings of other research: that most people mahve misconceptions about heat and temperature.
Using an infrared webcam to observe the structure of materials compared with what can be seen with the naked eye: I discovered that we can use infrared (like we can use x-rays), to see things that are invisible to the naked eye. I discovered that the reason the webcam can see more than our eyes is because warm things reflect and absorb light that webcams can see but our eyes cannot see.
Some animals, like snakes can see infrared light with their eyes but humans cannot.
Example Conclusions:
The principle of science, the definition, almost, is the following:
The test of all knowledge is experiment. Experiment is the sole judge of scientific “truth.”
But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints.
But also needed is imagination to create from these hints the great generalizations — to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess.
This imagining process is so difficult that there is a division of labor in physics: there are theoretical physicists who imagine, deduce, and guess at new laws, but do not experiment; and then there are experimental physicists who experiment, imagine, deduce, and guess.
When we say we are a pile of atoms, we do not mean we are merely a pile of atoms, because a pile of atoms which is not repeated from one to the other might well have the possibilities which you see before you in the mirror.
Example Summary:
The data from the above research and experiments suggests that heat is a result of jiggling/motion and that heating and cooling is the result of more or less movement.
By contrast, my survey results and others have shown that most people believe that hot and cold temperatures are properties of materials - They think, for example, that metal objects are cold whereas materials like polystyrene are warm or hot - even when both materials are measured as being at the same temperature.
More research (and funding) is required to investigate how to have more fun with heat!
How To Teach Science:
Research around the world indicates that at the end of their schooling, large numbers of students still hold many ideas, or conceptions, which are not in accord with the way that scientists understand our world. Here are some guidelines for teaching science at school.
A good scientific guide for students: What is heat
The Scientific Method:
The scientific method is one particular way to ask and answer scientific questions by making observations and doing experiments. Some people argue that there is no such thing as 'The Scientific Method' - make up your own mind:
The steps of the scientific method are to:
- Ask a Question
- Do Background Research
- Construct a Hypothesis
- Test Your Hypothesis by Doing an Experiment
- Record your Observations in a Table of Results
- Analyse the Data and Draw a Conclusion
- Communicate Your Results
- Source: Steps of the scientific method
No matter what your method is, it is important for your experiment to be a fair test:
A fair test means that you should set up your experiment so that everything is fair.
- You should only change one thing at a time, and note down the results.
- If you change more than one thing at a time, you can not tell which thing (variable) it was that affected the results.
Example Rubric (for teachers)
Here is the sample rubric: Heat Rubric
Engineering Task
Go to the following page to see the Engineering task referred to in the above rubric