S1 Planet Earth: Heat Transfer 1.Temperature 2. Cooling Curve 3. Conduction & Conductors 4. Investigation 5. Convection 6. Insulation 7. Emitting Heat (Radiation)

Lesson 1: Success Criteria By the end of this lesson you should be able to: Explain that temperature is measured in degrees Celsius (ºC) State that all hot objects emit heat as rays and is called infrared radiation. Discuss the increase or decrease in temperature of an object in terms of heat gain/loss. State that heat energy travels from hot objects to cold objects.

What is Temperature? Temperature is defined as how hot or how cold an object is. Temperature can be measured using an instrument called a thermometer with the unit of measurement being given as degree Celsius (ºC) When using a thermometer it is important to provide enough time for the reading to settle before noting the measurement.

What’s the Difference? The left hand picture is a digital thermometer with a metal probe. The precautions you must take when using this version are different to that of a standard mercury thermometer (pictured on the right). Can you think of what they are?

Heat is a form of Energy Heat is one of the six basic forms of energy and so is measured in joules (J). Heat energy will always move from a hot object to a cold object but the rate at which this happens is dependant on the temperature difference.

Temperature Increase & Decrease Every object contains some heat energy. When a substance/object rises in temperature, it gains heat energy. The particles of the object which has gained heat energy begin to vibrate more and more spacing themselves out (expand) There is a limit to how low temperatures can go. This low temperature limit is known as the Absolute Zero and is -273ºC.

Experiment 1 Aim: To investigate the movement of heat energy. Method: Fill a small beaker with 20ml of water and note the starting temperature. Use the blue flame of the Bunsen to roast a metal paperclip for 1 minute then drop into the beaker of water. Take the water temperature again. Results: Conclusion: Average temperature increase was ________ Starting Temperature (ºC) Finishing Temperature (ºC) Change in Temperature (ºC) 1. 2. 3.

Task 1 Read starting science book 1 page 105. Complete the following sentences in your jotter: 1. Heat energy is a description for ___________ particles. 2. Temperature is a description for ________ or ____________. 3. Heat is measured in _________ ( or ________). 4. Temperature is measured in ________________.

Lesson 2: Success Criteria By the end of this lesson you should be able to: Confidently carry out an experiment to collect data for a cooling curve Construct a cooling curve from data Explain the shape of a cooling curve in terms of heat loss, temperature of material and temperature of surroundings.

What is a Cooling Curve? A cooling curve is a line graph that represents the change of phase of matter, typically from a gas to a solid or a liquid to a solid. The independent variable (X-axis) is time and the dependent variable (Y-axis) is temperature.

Experiment 2 Aim: To generate data for the construction of a cooling curve graph to be drawn. Method: Boil water using a kettle and pour 30ml into a beaker straight away and note the temperature. For the first 5 minutes take a note of the temperature every 30seconds. Thereafter note the temperature at 2minute intervals for a further 20minutes. Results: Time (Min) 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Temperature (ºC)

Plot a Cooling Curve Graph Use your own results to plot a cooling curve line graph. Remember to follow the rules of S.L.U.R.P (Scale, Label, Units, Ruler, Pencil) for maximum points.

Task 2 Read Starting Science Book 1 page 106. Answer the following questions in sentences in your jotter: 1. In the graph shown on page 106, at which point (A, B or C) is the heat loss greatest and why? 2. Using the graph results, what is the rom temperature and how do you know? 3. If you were to double the quantity of heat in the experiment, how would this affect the shape of the graph? 4. Draw and label the graph at the bottom of page 106 describing how to read a cooling curve.

Lesson 3: Success Criteria By the end of this series of lessons you should be able to: Explain the term conduction as the ability of heat to travel through solid objects. Describe conduction in a solid in terms of the vibration of particles. Discuss why metals are good conductors and non metals are not.

Conduction of Heat In a solid, the particles are held together by a strong force of attraction causing them to continually vibrate about a fixed position. When a solid gains heat energy the particles vibrate more and cause further space to be created between them. This results in the solid EXPANDING. The jostling of particles causes the energy to be transferred. The transfer of this energy is called CONDUCTION.

Task 3 In your pairs (or groups) discuss whether each picture would be a good conductor of heart or a poor conductor of heat and why. As a general rule, a good conductor feels colder than an insulator at the same temperature, because it conducts heat AWAY from the body.

Experiment 3 Aim: To investigate how quickly heat is transferred in a solid (metal) Method: Using Vaseline, attach 5 drawings pins to a metal rod at equal distances apart. Light a Bunsen under the free end of the metal rod and time how long it takes for each drawing pin to fall. Results: Pin # 1 2 3 4 5 Time (s)

Conduction Investigation In your pairs, you will now choose whether to test different metals or different thicknesses of the same metal. You must come up with an aim and a safe method for your investigation. Have this checked by your teacher before you collect your equipment and carry out your experiment. Write up your findings on lined paper and draw a graph of your results.

Task 4 Read Starting Science Book 1 page 108 and answer the following questions in your jotter: 1. What is meant by saying that a metal spoon is a conductor but a wooden spoon is an insulator? 2. What type of substances are conductors and which are insulators from the list and create a table to show this: aluminium , wool , glass, tin , iron, copper , cork, plastic, air. 3. Explain why a saucepan is made of 2 different materials. 4. How could you protect yourself if you had to lift a hot plate? Why would this protect you? 5. Explain conduction in terms of ‘vibrations’ and ‘particles’.

Lesson 5: Success Criteria By the end of this series of lessons you should be able to: State that in a liquid or gas, heat travels by convection Explain that convection is when the hot liquid/gas rises because it is less dense due to the spaces between the particles being larger. Describe the pathway taken by liquids/ gases in a convection current.

What is Convection? When liquids and gases gain heat energy, their particles move faster and further apart causing expansion just like in a solid. The hot liquid or gas however becomes less dense and increase in volume. This is called CONVECTION.

Convection Currents A convection current is created by the movement of hot particles rising and the cooler particles falling. Examples of this include; heat rising from a radiator a hot air balloon rising liquid in a pot/kettle

Experiment 4 Aim: To investigate convection currents Method: Into a small beaker pour 50ml of cold water. Use the straw/ filter funnel to add a few crystals of potassium permanganate to one corner. Use a Bunsen to heat under the crystals and observe what happens. Results: The crystals coloured the water in a movement as shown by the arrows in my diagram :

Lesson 5: Success Criteria By the end of this series of lessons you should be able to: State that air is a poor conductor Explain how material that traps air can be used to reduce heat loss by conduction and convection Describe practical examples of insulators in a house/ building and also how to reduce heat loss from living things. State that a lid reduces heat loss by convection.

Air and Insulation Air is a poor conductor of heat, therefore trapped air can be used to prevent heat loss by conduction and convection. In pairs/ your groups can you think of as many examples of how air is used to trap heat in 2minutes.

Insulation Most forms of heat insulation will use trapped air. Many examples include: fibreglass loft insulation clothes/ fur thermos flask bubble wrap wool Other forms of insulators ensure that heat does not travel through it, for example, wooden spoons and plastic handles on pots/pans. Some insulators work to keep things cold such as a coolbox/ bag.

Task 5 Read starting science book 1 page 112. Answer questions 1-7 in sentences in your jotter.

Lesson 6: Success Criteria By the end of this lesson you should be able to: State that all objects emit heat as rays called Infrared Radiation State that infrared radiation can travel through a vacuum. State that infrared radiation travels very fast.

Infrared Radiation All hot objects radiate heat rays called infrared radiation. This radiation travels in straight lines and in all directions. Unlike conduction and convection, radiation can travel through a vacuum and at the speed of light. We can use infrared radiation cameras to detect small changes in temperature meaning that they are very useful for medical treatments, police helicopters during chases and in the fire brigade.