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GCSE Core Gateway Science B P2: Living for the Future (Energy resources) “We are what we repeatedly do. Excellence, therefore, is not an act but a habit” A.Dart Page 1 A.Dart Page 2 Unit Page Completed By 2a 2b 2c 2d 2e 2f 2g 2h Use the activities and past exam questions in this booklet to plan and support your revision ready for the B2C2P2 science exam. REVISION WEBSITE – The following website is available for you to use to support your revision and help you answer the exam questions in this revision guide http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway/ A.Dart Page 3 A.Dart Page 4 P2a: Collecting energy from the Sun Grade E Understand the properties of photocells. Recall that DC electricity is current in the same direction all the time. Describe how the Sun’s energy can be harnessed. Grade C Describe the advantages and disadvantages of photocells. Describe advantages and disadvantages of wind turbines. Grade A Describe how light produces electricity in a photocell. Describe the factors determining the current and power produced in a photocell. Explain why passive solar heating occurs. Recall that an efficient solar collector nust track the Sun across the sky. Key Information Photocells are devices that transfer light energy directly into electrical energy. They produce DC direct current - electricity. This is electricity in which the current moves in the same direction all the time. Photocells have no moving parts. They do not need to be connected to the National Grid, so no cables are needed and they can work in remote locations. For example, they are used to power the lights for some road signs. The output of photocells depends on the surface area that is exposed to light. For a given light intensity, the larger the area, the greater the power output. Photocells consist of two types of silicon crystal. When light energy is absorbed by the silicon: negatively charged electrons are knocked loose from the silicon atoms in the crystal the electrons flow freely, creating an electric current.(Higher Tier) Revision Ideas 1. Draw a mind map for the P2 unit. Add pictures and colour code key words and information 2. Write some practice exam questions for other students to try, make sure you write a mark scheme. A.Dart Page 5 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is photocells The solar sunFLOWER™ lamp is used to light a footpath. Photocells on top of the lamp transfer light energy from the Sun into electricity. This energy is stored in a battery to light a bulb when it gets dark.Write down one advantage of using photocells to produce electricity.The sunFLOWER™ is shaded by trees.Why is its power reduced? Describe how light from the Sun produces electricity in a photocell. In your answer, use ideas about A.Dart • energy • atoms • electrons. Page 6 Important words list Direct Current surface area Photocell Electrons Silicon atoms Crystal A.Dart Page 7 P2b: Generating Electricity Grade E Describe how movement of a coil or magnet generates electricity by means of the dynamo effect. Recall that a generator produces Alternating Current AC. Recall that a battery produces Direct Current DC. Describe the main stages in the production and distribution of electricity. Recognise energy waste in a simple power station. Use the energy efficiency equation. Grade C Describe and recognise ways to increase the dynamo effect. Describe and interpret AC using a voltage / time graph. Describe how simple AC generators work. Describe how electricity is generated at a conventional power station. Grade A Use the energy efficiency calculation to calculate useful energy output, total energy input or wasted energy. Key Information Most of our electricity is generated in power stations by burning fuels. You need to know and understand how power stations work and how electricity is transported to our homes and factories. Revision Ideas 1. Draw a diagram of a Power Station. Label all the places where energy is being lost and how this loss is minimised. 2. Name two energy sources that are burned as fuels in a Power Station; one renewable and one non-renewable. A.Dart Page 8 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about Generating electricity Wind turbines are often located in groups on wind farms. The energy of the wind can be transferred into electrical energy by the turbines. Describe how electricity is generated by the turbines. Explain how the current from a generator can be increased. Important words list Generator Alternating current Dynamo effect Coil Magnet Magnetic field A.Dart Page 9 P2c: Global Warming Grade E Understand that gases in the atmosphere prevent heat radiating into space Recall and recognise this as the greenhouse effect. Recall and identify greenhouse gases. Describe reasons for climate change caused by global warming. Describe difficulties of measuring Global warming. Explain why climate scientists should share data. Grade C Describe how certain electromagnetic wavelengths are absorbed by gases in the atmosphere. Recall and identify natural and man-made sources of greenhouse gases. Describe scientific evidence for and against the idea of man-made global warming. Distinguish between opinion and evidence based statements about global warming. Grade A Explain the greenhouse effect. Explain how scientists can agree about the greenhouse effect, but disagree about whether human activity is affecting global warming. Key Information There is a large amount of discussion amongst scientists, politicians and the general public about the reasons for global warming. The greenhouse effect is considered to be a proven scientific explanation. Discussions will continue as more evidence and sources are published and shared with the Science community who then in turn have to communicate complex scientific issues to the wider population. Revision Ideas The greenhouse effect Produce a leaflet explaining the greenhouse effect. Global Warming Write a letter that supports the idea that human activity is causing global warming. A.Dart Page 10 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about global warming and the greenhouse effect. Some scientists believe that increased CO2 levels arising from the combustion of hydrocarbons lead to global warming because CO2 is a greenhouse gas. Carbon capture and storage, CCS, is being developed as a method for removing CO2 produced by combustion. Different gases have different contributions to global warming. State two factors that affect the contribution of a greenhouse gas to global warming. There is much international concern that an increase in atmospheric concentration of carbon dioxide and methane may lead to global warming and climate change. (a) Carbon dioxide and methane are both greenhouse gases (i) What type of radiation is absorbed by methane molecules and what effect does this radiation have on these molecules? Suggest why some scientists are more concerned about carbon dioxide as a greenhouse gas than methane Carbon dioxide is a greenhouse gas that has been linked to climate change. What happens within a carbon dioxide molecule when it absorbs infrared radiation? (6marks) Important words list Carbon dioxide gas Combustion Fuel Absorb Radiation Greenhouse gases Methane Global warming A.Dart Page 11 P2d: Fuels for Power Grade E Grade C Recall that the unit of Power is the watt or kilowatt. Understand that the cost of using electrical appliances depends on their Power and the time they are used for. Use the Power equation to calculate the Power of an appliance. Recall the use of transformers to increase or decrease voltage. Use the Power equation to calculate the Power of an appliance, including conversion of units of Power. State that the unit of electrical energy supplied is the kilowatt hour. Calculate the number of kilowatt hours given the Power and the time used. Use the energy supply equation to calculate energy supplied. Calculate the cost of energy supplied. Grade A Use and manipulate the Power equation. Use the kilowatt hour as a measure of energy supplied. Describe the advantages and disadvantages of using off peak electricity in the home. Explain how an increased voltage reduces current, thus decreasing the energy lost from cables as heat. Key Information Fuels are energy sources that release heat energy during burning. The three common fuels used in power stations are fossil fuels; renewable biomass (wood, straw, and manure); Nuclear fuels – uranium mostly but sometimes Plutonium. Power = voltage x current Energy supplied = power x time Revision Ideas 1. Draw simple diagram of the National Grid and label it showing the following; power station; step up and step down transformers; pylons; consumer. 2. Produce some flash cards for the key words underlined in the text above ( word or equation on one side and definition or how equations are used). A.Dart Page 12 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about producing electricity in power stations (6marks) Electricity is produced by Power Stations. Describe briefly how Power Stations use different energy sources to do this, identifying three named energy sources. Electrical energy leaves a Power station through a transformer. Describe how and why transformers are used by the National Grid. If a generator in a Power Station produces a voltage of 20,000 V it will generate a current of 60 A.Calculate the Power output of this generator. Important words list Power Station Fuels Renewable and nonrenewable fuels Power National Grid Transformers Step up / Step down A.Dart Page 13 P2e: Nuclear radiations Grade E Recognise beneficial and harmful effects of radiation. Recall the 3 types of nuclear radiation. Understand that nuclear radiation causes potentially harmful ionisation. Describe how to handle radioactive materials safely. Describe nuclear waste as radioactive and harmful, but not responsible for Global warming. Grade C Describe examples of beneficial uses of radiation. Understand that radioactive materials give out radiation over time. Describe the relative penetrating power of alpha, beta and gamma radiations. Understand that nuclear radiation can form positive ions when atoms lose electrons. Understand that nuclear radiation can for negative ions when atoms gain electrons. Recall that Uranium is a nonrenewable resource. Recall that Plutonium is a nuclear waste product and can be used to make nuclear bombs. Describe methods of disposing of radioactive waste. Grade A Explain how ionisation can damage the DNA in human cells. Describe the advantages and disadvantages of nuclear power. Explain the problems of dealing with radioactive waste. Key Information The 3 types of radiation are alpha, beta and gamma. They each have different penetrating powers. Revision Ideas 1. Make some true / false statements cards. Practice sorting them into true/false piles. Time yourself and see if you can beat it the next day. 2. Write a script for a “TV drama” where the characters are concerned about the dangers from a new Nuclear Power Station being situated near their homes A.Dart Page 14 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about infrared and microwave cookery. Alpha, beta and gamma radiations all have different properties. Describe their penetrating powers and use these to explain how each type of nuclear radiation can be used. Describe the advantages and disadvantages of nuclear power. (6marks) Important words list Alpha, beta, gamma Nuclear radiation Penetrating power Lead, aluminium, paper Negative ions, positive ions Electrons Ionisation Uranium Plutonium A.Dart Page 15 P2f: Exploring our Solar System Grade E Identify the relative positions of the Earth, Sun and planets. Recall the make-up of the Universe. Explain why stars give off light and can be seen over long distances. Recall that radio signals take a long time to travel through the Solar System. Compare the resources needed by manned and unmanned spacecraft. Describe why unmanned spacecraft are sent into space. Grade C Recall the relative nature and size of the features of the Universe. Describe a light-year. Describe the difficulties of manned space travel between planets. Recall that unmanned spacecraft can withstand conditions lethal to humans. Compare how information from space is returned to Earth from different distances. Grade A Recall that circular motion requires a centripetal force. Understand that gravitational attraction provides the centripetal force for orbital motion. Explain why a light-year is a useful unit for measuring long distances. Explain the advantages and disadvantages of using unmanned spacecraft. Key Information When we look at the night sky we can sometimes see the Moon, artificial satellites, planets in our Solar System and the billions of stars which make up the Universe. Revision Ideas 1. Produce a revision card on the relative positions, sizes and nature of planets, stars, comets, meteors, galaxies and black holes. 2. Make an information leaflet describing, explaining and comparing the differences between manned and unmanned spacecraft. A.Dart Page 16 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about Exploration of our Solar System The first spacecraft to visit the Moon were unmanned robots. By 1969, humans had landed on the Moon. (a) Suggest two reasons why manned spacecraft are not used to explore other planets? (b) It costs a large amount of money to send spacecraft to other planets. Scientists often have to persuade governments that this is a good way to spend money. Suggest two reasons scientists might give to persuade governments that it is worthwhile. (c) Compare how information from space is returned to Earth from different distances. . (6marks) Important words list Reflection Speed of light Long distances Manned and unmanned spacecraft Stars, planets, comets, meteors, galaxies and black holes. A.Dart Page 17 P2g: Threats to Earth Grade E Understand the origins of the Moon. Recall that large asteroids have collided with the Earth in the past. Recall that asteroids are rocks. Describe the consequences of a collision with a large asteroid. Describe the make-up of a comet. Describe a Near Earth Object (NEO). Describe how NEO’s may be seen. Grade C Describe how a collision between two planets can result in an Earth-Moon system. Describe the origin and orbit of asteroids. Describe evidence for past asteroid collisions. Describe the origin and orbit of comets. Describe how the speed of a comet changes as it approaches a star. Describe how observations of NEOs are used to determine their trajectories. Explain why it is difficult to observe NEOs. Grade A Discuss evidence for the Earth-Moon system as a result of a collision between two planets. Explain the location of the asteroid belt. Explain why the speed of a comet changes as it approaches a star. Suggest and discuss possible actions to reduce the threat of NEOs. Key Information Most people ignore the threat of asteroids collisions with Earth. This section shows that the threat is real and has proved to be lethal many times in the past. An understanding of what is and can be done to avoid such collisions in the future. Revision ideas; 1. Research evidence that can be used to explain the extinction of the dinosaurs. 2. Do a comparison of asteroids and comets, showing their similarities and differences. A.Dart Page 18 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about threats to Earth. Scientists think that the Earth-moon system was caused by the collision of two planets. What evidence is there that this is how the Earth and Moon were made? There is an asteroid belt between Mars and Jupiter. In the past some asteroids have collided with Earth. Describe some evidence for these collisions. What are NEOs? Why/how do scientists study them? (6marks) Important words list Collision Orbit Asteroids Evidence NEO Crater Hot rocks Climate change Extinction A.Dart Page 19 P2h: The Big Bang Grade E Describe the Big Bang Theory for the origin of the Universe. Recall the properties of stars. Understand that not even light can escape from Black Holes. Recognise change in accepted models of the size and shape of the universe over time. Describe and recognise the Ptolemaic and Copernican models and how they differ from each other and the modern day model of the universe. Grade C Recall the movement of galaxies away from Earth. Recall that microwave radiation is received from all parts of the universe. Describe the end of the lifecycle of a small star and a large star. Describe the evidence or observations behind Copernicus and Galileo’s new models of the Universe. Explain how technological advances contributed to the new models. Grade A Explain how the Big Bang Theory accounts for redshift in more distant galaxies. Explain how the Big Bang Theory accounts for the age and starting point of the Universe. Describe the life history of a star. Explain the properties of a black hole. Explain why Copernicus and Galileo’s new models were considered controversial. Key Information There are a number of theories about how the Universe was formed and how it will continue to evolve. This section develops ideas about the evolution of the Universe and it’s possible future. The Big Bang theory is considered as the most recent theory to explain how the Universe was formed. Revision Ideas 1. Draw a picture showing end of the life ‘cycle’ of small and large stars . Cut it up and make it into a jigsaw puzzle. 2. Produce a timeline for the changing models of the Universe. A.Dart Page 20 QWC Question (6 marks) When answering a QWC question remember the following points: Use correct science vocabulary, organise ideas, avoid using “it”, and write in full sentences. You also need to try and keep you answer relevant to the question. A good way to do all this is to write out important key vocabulary and then use them to structure your answer. Underlining them will help you keep track and highlight to the examiner your good use of key terms, Question – This question is about the Big Bang Theory People often think about how the Universe and stars began. One theory that explains the start of the Universe is the Big Bang. The Big Bang theory helps us to understand the movement of galaxies. (a) What does the Big Bang theory tell us about the movement of nearby galaxies? (b) What does the Big Bang theory tell us about the movement of distant galaxies? (c) Scientists have detected microwave radiation reaching the Earth. This radiation started soon after the Big Bang. Where does this radiation come from? (6marks) Important words list Big Bang theory Stars Galaxies Microwave radiation Universe Expanding Spectrum Red shift A.Dart Page 21 A.Dart Page 22