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Green Science
Energy
What is energy?
BATs Recognise that we get
our energy from our food 3
Recognise Joules as unit of energy 4
Interpret information about energy content of foods 5
What is energy?When something
happens an energy change happens.
Look at the demosWhat changes are
happening?
Types of energy
light
sound
electrical
Gravitationalpotential
kinetic
chemical
Elastic/spring heat
How do we measure energy?
• Energy is measured in …
JOULES (J)1000 Joules = 1 kilojoule (kJ)
How many kJ would there be in 2,500 J 2.5kJ
Where do we get our energy from?
The energy we need comes from food
• Look at the food labels• Find Nutritional Information – look for
energy for 100g/ml of each food• Play food ‘Top Trumps’• Which food has the most and least
energy?
How much energy in food?
You will need:A cork with a pin!!!Boiling tubethermometerSmall measuring
cylinderClamp/standBench matGogglesPieces of food
Method:• Set up the clamp stand• Measure 25 ml water into a
boiling tube.• Hold boiling tube in clamp • Take the temperature of the
water• Place a piece of food
carefully on the pin• Set light to the food and
place under the boiling tube.• Measure the temperature
after the food has all burnt
How much energy in food?
food Temperature at start 0C
Temperature at end 0C
Difference in temperature0C
How much energy in food?
Draw a graph of the results of your experiment
OR
Pick 5 foods from the labels you have looked at
Draw a graph to show how much energy each food has per 100g/ml
Plenary
• List all the things you have done today
• What types of energy were involved
• E.g ate breakfast – chemical energy
• Walked to school - …………….energy
• Have you achieved your BAT’s?
Which is the best fuel?
BATs
Describe briefly what happens when a fuel burns 3
Assess the risks in doing an experiment with fuels 4 (
Evaluate which fuel is the best and why 5
Rearrange these words to reveal 5 types of energy:
ieikntc
lcmhceia
nosud
lcrcleetia
isleatc
kinetic
chemical
sound
electrical
elasticWhat types are missing? Sticker if you can get them!!
Fuels
coal
gas
oilwood
Petrol/diesel
nuclear
peat
What happens when fuels burn?
When fuels burn it is called
COMBUSTION
Fuel + _ _ _ _ _ _ carbon dioxide + _ _ _ _ _ + heat
oxygenwater
Which is the best fuel for heating water?
Fuel Temperature at the start
(OC)
Temperature after 3 mins
(OC)
Temperature change (OC)
Ethanol 20 29 9
Wood 20 21 1
Candle wax 18 25 5
gas 18 65 47
Copy this table into your books – leave the names of the fuels for now
Predict which one will be the best and why
PbyPYou are going to do an experiment to find
out which is the best fuel.What safety precautions will you need to
make?Write a risk assessment for the experimentSome you may not of thought of …• Listening to advice and suggestions• Not being too overpowering or bossy!• Following instructions
This can be used as a piece of work you could submit for PbyP – Managing Risks!
Which is the best fuel for heating water?
You will need: As a table choose 3 fuels to test.
Work in pairs – each pair tests one fuel.
1. Set up apparatus as in diagram
2. Pour 20ml water into a boiling tube.
3. Take temperature of water before heating
4. Light fuel and heat the water for 3 minutes
5. Take the temperature of the water again
Goggles, stopwatch
Measuring cylinder
Heatproof mat
Tin lid
fuel
thermometer
Boiling tube
Clamp and stand
Which is the best fuel for heating water? Evaluating
• Which fuel gave the largest rise in temperature?
• Which fuel was the easiest to light?
• Which was the ‘cleanest’ fuel (least soot)?
Overall the best fuel for heating water is ……..…., because ………………………..
Plenary
In your team decide how successfully..
• Your risk assessment worked
• Your group completed the experiment
Could you make any improvements to either of the above?
Lesson 3 –How were fuels formed?
BATs
Identify some common fossil fuels (3)
Describe how fossil fuels were formed (4)
Explain why fossil fuels are called non-renewable (5)
Analyse some of the advantages and disadvantages of using fossil fuels (6)
Starter
Which of the following are not fuels?
• Gas• Coal• Heat• Electricity• Peat• Oil• nuclear
Fuel How easy to light?
Does it burn cleanly?
How much energy is released?
coal difficult no 30 kJ per gram
natural gas very easy yes 55 kJ per gram
oil easy no 45 kJ per gram
1. Which fuel is the easiest to light?2. Which fuel burns most cleanly? What does this mean?3. From which fuel do we get petrol?4. Which fuel gives the most energy if one gram is burned?5. Which fossil fuel is a solid, which is a liquid and which is a gas?6 a Why do you think petrol is used in cars instead of coal or natural gas? b Why do you think lots of homes use natural gas for central heating instead of coal or oil?
Which is the best fuel?
Fossil Fuels
Coal, oil and natural gas are examples of
FOSSIL FUELS.
Why do you think they are called this?
Fossil FuelsCoal oil and gas were formed millions of
years ago from dead plants and animals.• There is a finite amount of these materials
on the Earth so they will run out eventually.• Once they are used up they cannot be
regenerated and used again.• These fuels are called NON-RENEWABLE
energy resourcesUranium is a radioactive material that is also
non-renewable, but is not a fossil fuel.
Coal Formation
Predict what happened next
How coal was formed
About 300 million years ago, plants photosynthesized and stored the Sun’s energy.
Dead plants fell into swampy water and the mud stopped them from rotting away.
Over the years, the mud piled up and squashed the plants.
After millions of years under this pressure, the mud became rock and the plants became coal.
Coal
Oil formation
Predict what happened next
How oil was formed
Oil is also biological in origin. Millions of years ago tiny animals lived in the sea. Like now their ecosystem was dependent on heat and light from the Sun and photosynthesis by plants. When they died they fell into mud and sand at the bottom of the sea but didn’t rot away.
Over millions of years, they got buried deeper by the mud and sand. The temperature and pressure (caused by the weight of the sediments and deep burial) changed the mud and sand into rock and the dead animals into crude oil and natural gas.
This sample of crude oil was formed in Southern England. Crude oil formed in other parts of the world can be very different in appearance and viscosity.
How were coal and oil formed?
• Read p 134-5 in the Go Science! Book
• Create a story board (with notes) for how either coal or oil were formed
• Try to be neat and use colour!
How true is it to say that all our energy comes from the Sun?
Plenary – discuss in groups
Greenhouse effect
From air trapped in Antarctic ice, we have a good idea of CO2 concentrations going back 160,000 years.
Which label goes with each picture?
200ppmCO2
300ppmCO2
We also know the temperatures over the same period.The very warm interglacial period of 130,000 years ago was accompanied by CO2 levels of around 300 ppm.
The previous great Ice Age had CO2 levels around 200 ppm.
Normally the Earth absorbs heat and emits heat at the same rate. Because of this the temperature remains constant.
Certain gases, like CO2 and methane, act like a greenhouse. They let heat in but do not let it out.This means: the more CO2 there is, the hotter planet Earth is!
Earth
Heat from sun
Heat loss
More CO2
Earth
Heat from sun
Heat loss
hotterAnd hotterAnd hotter!
balanced same temp
Greenhouse effect
Choice of Activities – can be submitted for PbyP
Either1. Make a powerpoint to show how Coal
and/or oil was formed2. Explain using powerpoint what The
Greenhouse effect is and what causes it to happen (e.g. burning fossil fuels)
3. Explain how to reduce the effects of the Greenhouse effect and Global Warming e.g recycling, using renewable energy sources
Plenary
• Look at someone else’s powerpoint
• Suggest 1 strength of their work
• Suggest one way they could improve the work
• Be thoughtful and
constructive please!!
Holiday Homework – finish today’s powerpoint and submit it for PbyP. Merry Christmas!!!
