Lesson 1

Unit Title: Heating and cooling 
Caretaker:  MDB  kkkkkkk

Unit No   
8I

Lesson Title:  Hot Stuff

PLEASE NOTE - I have left it up to teachers to decide what the pupils record in books so timings may be wrong.

NC Ref: 
 

Objectives:    

MK - use thermometers, temperature scale, units used. 'temperature, heat, degrees Celsius, joules 
SK -  distinguish between heat (as energy) and temperature, heat energy is thermal energy, energy flow as temp. difference.
CK -  specific heat capacity

Lesson outline: The basis of the lesson is to get over that temperature and heat energy though related are not the same.  

Starter activity: Place a large beaker and a small beaker of water filled with water on the front desk and take the temperature. (~20˚C). So they have the same temperature. Then heat them up as you talk about different temperatures. Boiling and melting point of water, body temperature etc. Go back to the beakers and take the temperatures (could use data logging). The big beaker will now have a different lower temperature. Ask pupils to think why and say you will come back to this.  There is an opportunity to talk about fair tests and in particular what is unfair about this test. Different Bunsen's may give out different amounts of heat energy and the glass in a bigger beaker may absorb more energy.

Main course: Class practical to mix different amounts of waters at different temperatures.

All the pupils do is get amounts and temperatures of their own choice and mix them together taking a final temperature and filling in the table. There is no set out conclusion to the experiment, but do outline that the amount of water as well as the temperature has an effect so they can work out that HEAT IS A FORM OF ENERGY; TEMPERATURE IS A DESCRIPTION OF HOW HOT OR COLD SOMETHING IS. In this way a bath at 60˚C has a lot more heat energy than a cup of water at 60˚C, the temperature is the same.

Plenary: It is plausible that the plenary could be a question and answer session or that the teacher simply utilises the questions on p104-105 exploring science 8. Worksheet 8Ia/4 would also be good to reinforce what has been learnt. Maybe on projector or individual worksheets (not ordered)
 

Timings:

10 mins

40 mins

10 mins

Homework Suggestion: 
To find out what is a conductor is with 3 examples.

Resources: Large beakers, Bunsen burners etc., thermometers (at least 30).
 

Lesson 2 

Unit Title:  Heating and Cooling
Caretaker:  MDB

Unit No   
8I

Lesson Title:  Conducting Heat

NC Ref: 
 

Objectives:    

MK -  examples and uses of conductors, heat travels through solids by conduction. 'conduction, conductor'
SK - explain conduction using particle model, metals are good conductors because particles are closely packed. 
CK -  Differences between Fahrenheit, Celsius and Kelvin.

Lesson outline: To understand how temperature travels through a solid (particle model). What makes a good conductor/ insulator.

Starter activity: Get the pupils to touch firstly the wooden top of the table and then the metal part of their stool. Which feels warmer? Are any of them producing heat? They must have the same temperature (room) what is happening? (The reason is body temperature is 37˚C and the metal is better at conducting heat away from the hand.
Also it is worth discussing what pupils learnt at KS2, clothes keep us warm by trapping our body heat not by being hot themselves. Dissuade pupils from talking about letting the cold in, heat energy goes from hot to cold.

Main course: Work sheet 8Ib/1 (side 1) on projector on board to give instructions. 8Ib/1 (side 2) handed out. The practical is pretty self explanatory. The temperature sensors can be replaced by drawing pins attached by Vaseline.

A good demonstration to do once the sheet has been completed is with a single rod with a number of drawing pins / temperature sensors on so you can show the temperature increasing along the rod. This leads on well to the final part of the lesson.

Plenary: What does the fact that the whole of the rod doesn't instantly become hot when placed in the Bunsen flame? The heat must be transferred along the rod by something happening. Get the pupils to stand in a row and closely together. Pretend to be the Bunsen burner at one end. This pupil having more energy starts to vibrate more. Also the person next door will start to vibrate more. This vibration (or heat energy) is passed along the line - CONDUCTION. It is this heat energy that causes the temperature to increase. Please make sure that the particles don't start to vibrate, their vibrations are made bigger. Conduction Flash shows this well. Also shows why solids expand when heated. Their particles (same size) take up more space. This needs to be in books.
 

Timings:

10 mins

20 mins

15 mins

15 mins

Homework Suggestion: What makes a good insulator. Think about solids liquids and gases.

Resources: Class set copper rod, glass rod iron rod, drawing pins (loads) Vaseline, stop clocks, tripods etc., data-logging equipment
if the teacher requires it (temperature sensors).

Lesson 3  

Unit Title:  Heating and Cooling
Caretaker:  MDB

Unit No   
8I

Lesson Title:  Changing Size

NC Ref: 
 

Objectives:    

MK -  Insulators, expansion with heat, heat through liquids and gases by convection, radiation doesn't involve movement
of particles. Heat travels through space by radiation. 'convection, radiation, expand, contract, insulator'

SK -   expansion due to particle theory, why hot fluids rise, convection currents. 'fluid'
CK -  applying ideas about convection to practical situations.

Lesson outline: To show energy transfer in liquids and gases is not the same as solids.

Starter activity: Demonstrate ball and ring experiment. Ask the pupils what this tells us. Conduction flash shows this quite well. Also if you heat up a round bottomed flask full to the brim with water with a capillary tube placed in it you can see the water rise up the tube. There must be a reason for this. Use pupil model of conduction again from last lesson except this time observe how the line gets longer as to stop the pupils knocking in to each other. The round bottomed flask is actually a primitive thermometer. This will also remind the children about conduction and is a nice link to the fact that gases and liquids don't transfer heat energy in this way.

Main course: Demo. Drop a crystal of potassium manganate down a tube into a beaker of water. then heat the beaker and observe the trail of dye. Slide 20 of Boardworks shows this well. The cycle is due to warm less dense water rising, losing some heat energy becoming more dense and sinking to the bottom. It is the same process that distributes heat energy in gases. Cut and complete Worksheet 8Ic/2. Outline liquids and gases are both classed as fluids because they flow.

Both conduction and convection need particles to pass on the heat energy but the suns energy gets to earth through a vacuum leading to a third way. Use p111 Exploring Science 8 to read through and answer the questions to understand this. Discuss what materials absorb radiation (black) and what materials reflect radiation (silver, white). Black t-shirt on hot day good example.

Plenary: Worksheets 8Ic/3, 8Ic/4 and 8Ic/5 provide good questions to reinforce pupils understanding. Question 3 on 8Ic/5 can not be answered because insulators have not been covered. Could work through on projector or use worksheets (on technicians list).
 

Timings:

15 mins

15 mins

15 mins

15 mins

Homework Suggestion: Any of the worksheets from the plenary.
 

Resources: Large round bottomed flask, capillary tube in bung, potassium manganate,

tube for placing manganate crystal, Bunsen burner etc.
 

Lesson 4 

Unit Title:  Heating and Cooling
Caretaker:  MDB

Unit No   
8I

Lesson Title:  Save It!

NC Ref: 
 

Objectives:    

MK -  Fossil fuels will run out, can slow this down by saving energy, insulating stops heat loss 'insulate'
SK -  Some ways of insulating a house to reduce heat loss, most insulation relies on trapped air.
CK - the approximate energy savings made by different types of insulation. 

Lesson outline: How we can restrict energy loss, especially from houses.

Starter activity: Quick overview of energy topic from year 7. What are fossil fuels. Will they run out. How can we slow down how quickly they run out. For example in a house where does the energy escape to (hot to cold) and through what. Pupils will be surprised that heat is lost through walls and roofs as well as windows and doors. This is shown very well on page 112 (houses with snow) and page 113 (heat loss of house). The snow not melting is a very good example of how loft insulation stops heat energy escaping.

Main course: Good insulating materials. Using the equipment provided try and keep the small beaker as warm as possible by insulating between the two beakers. There are 2 ways.

1 - Before the pupils dive in point them into the right direction brain storming about the three types of heat transfer. Once the whole class has completed their design go round with a kettle of water and fill the pupils small beakers. Take the temperature every 30 seconds for ten minutes. The group with the smallest drop wins stamps.                            

2 - Each different group uses a different material and see which holds the temperature in the way outlined above.

Plenary: The students should have realised that good insulators usually rely on trapped air. This needs pointing out and writing in books. Using exploring science 8 p112 &113pupils to do a small piece of writing on how they will save money on fuel bills (and save the environment) when they own a house. Also if time opportunity to discuss futuristic house on page 113.
 

Timings:

15 mins

30 mins

15 mins

Homework Suggestion: What energy saving additions have your parents got on their house. Tell them to get the others done!
 

Resources: Exploring Science 8
 

Lesson 5 

Unit Title:  Heating and Cooling
Caretaker:  MDB

Unit No   
8I

Lesson Title:  Changing State

NC Ref: 
 

Objectives:    

MK -  Changes of state happen at fixed temperatures, freezing point and melting point of a substance are the same, heat energy changes accompany changes of state. 'boiling point, evaporate, condense, heat energy, melting point, freezing point'
SK -  When changes of state occur - temperature stays constant, heat energy is returned to their surroundings when a substance freezes or condenses, liquids can evaporate below the boiling point, evaporation results in the remaining liquid being cooler.
CK - relative humidity and how it is measured 

Lesson outline: To understand the heating and cooling curves. Revision of the three states of matter.

Starter activity: Where do puddles go? The water doesn't boil it's never 100˚C outside. Therefore water must evaporate below it's boiling point. What (remembering the rest of the topic) could be responsible for the change of state. (both boiling and evaporation). Could be heat energy transfer to the particles giving them enough energy to leave the other liquid particles.
 

Main course:  Student demo. Get 9 pupils to stand in three lines of three with there arms rigid onto each others shoulders, they are a solid, rigid with a fixed volume. They are on a fixed point but should be vibrating. If you heat up the solid you can get the solid particles enough energy to break the rigid bonds between them. Make them now hold hands. They are now a liquid, free to move around but still connected by weak bonds. If you heat them up further occasionally have enough energy to escape and move around the class room, they are now a gas with no forces of attraction with each other. For a diagrammatic representation,  slide 7-9, boardworks

Slide 32 onwards, boardworks shows the heating curves. The reason for the 'flat bits' on the curve is that during this time all the heat energy from the Bunsen burner is all going to breaking the bonds to change states of matter, it is not going to  heating up the substance, therefore temperature is constant even though energy is being added. This is why liquid water doesn't go above 100˚C, the more energy you add the more water evaporates. If you have a higher group you can talk about the cooling curve, the flat points are due to energy been given out as bonds are made. Therefore the temperature remains constant even though energy is still being released to the surroundings.

As a final point for higher pupils. Place some ethanol at room temperature on the back of pupils hand. it will feel cold, because the ethanol is using energy from the hands to evaporate. This is why elephants throw water over themselves.

Plenary: Start heating a piece of ice on a tin plate. Keep referring back to this as a change of state happens asking a pupil to reinforce what has been learnt. Question and answer. Questions on page 115 exploring science 8.
 

Timings:

10 mins

15 mins

20 mins

10 mins

Homework Suggestion: Revision for test. Worksheet 8Ie/3
 

Resources: Tin lid, Bunsen etc., Ice, thermometer