UNIT TITLE:    HEATING AND COOLING LESSONS

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.

Beaker 1 Beaker 2 Final Beaker
 Amount of water (ml) Temp. (˚C)
 Amount of water (ml) Temp. (˚C)
 Temp. (˚C)

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.

Video Clips: None

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

Worksheets: Worksheet 8Ia/4 if needed (not ordered).

Risk Assessment: Boiling water is hot!!

 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. Video Clips: None 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). Worksheets: Second side of 8Ib/1 Risk Assessment: The metal rods stay very hot for a long time onwards.

 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! Video Clips: None Resources: Exploring Science 8 Worksheets: None Risk Assessment: Hot water

 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 Video Clips: sci in action - solids liquids & gases Resources: Tin lid, Bunsen etc., Ice, thermometer Worksheets: Worksheet 8Ie/3 Risk Assessment: Wash ethanol off the back of the students hands straight away.