C5 Chemicals of the Natural Environment Route map Over the next 12 lessons you will study : Friday 21 October 2011 C1.1 Chemicals in four spheres C1.2 Chemicals of the atmosphere C1.3 Chemicals of the hydrosphere C1.4 Chemicals of the lithosphere End of module test C1.5 Silicates of the lithosphere C1.6 Chemicals of the biosphere C1.7 Human Impacts on the environment C1.8 Metals from the lithosphere C1.9 Metals from the lithosphere (Part 2) C1.10 Metals from the lithosphere (Part 3) C1.11 Structure and bonding in metals C1.12 The life cycle of metals
C5.7 Human impact on the environment Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand how elements cycle and are recycled in environment. </li></ul><ul><li>Understand and describe the nitrogen and carbon cycle </li></ul><ul><li>Understand how humans can have an impact on these cycles. </li></ul>Friday 21 October 2011 First activity: Human burning fossil fuels since 1750 have change the amount of carbon dioxide in the air. In a normal day, how often do we burn fuel ? Make a list of when we as humans burn fuel and what is released into the atmosphere when we do. Literacy: Human impact, environment, habitat, elements, cycle, recycle, nitrogen, carbon, nitrogen cycle, carbon cycle, biosphere, hydrosphere, lithosphere and atmosphere. Numeracy: The amount of carbon dioxide in the air is around 350 parts per million. This is only 0.03% of the total atmosphere. Around the year 1750, it was recorded at 270 parts per million. Human activity has led to a 25% increase in CO 2 levels. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on creative thinkers to try and think how we can help reduce our impact on the environment Team workers Effective participators Self managers
C5.7 Human Impacts on the Environment Extension questions: 1: Give an example of a compound or chemical that contains carbon in each of the four sphere ? 2: Looking at the carbon cycle, give two way in which carbon flows into the atmosphere and two way in which carbon is removed from the atmosphere ? 3: How our humans affecting atmosphere CO 2 levels ? 4: What happens to soil nitrogen levels (nitrate) with repeated use by farmers and how do farmers add nitrogen back into the soil ? Know this: a: Know that key elements like nitrogen and carbon are cycle between spheres over time. b: Know that human activity can disrupt the cycling of elements c: Know that fertiliser is made using the Haber Process Friday 21 October 2011 Introduction: Elements are constantly being cycled between the different spheres of the Earth. When things die, the elements may return to the lithosphere, hydrosphere and atmosphere. Carbon is a very important element in the biosphere. As we burn so much fossil fuels currently, more and more carbon is in our atmosphere. The impact of this is that we are contributing to global warming. Nitrogen is essential for life as well. Many different forms of nitrogen are found and also cycle between the spheres. In order to grow more food we add nitrogen to the lithosphere in the form of fertilisers. This is causing things to grow that we don’t necessarily want....
Look at the photograph and information and answer all the questions: Cycling of many plant nutrients, especially nitrates, potassium, phosphates and carbon follows the cycling of decaying organic matter form the bodies of dead animals and plants. This organic matter becomes food for decomposers. As organic matter is broken down to simpler compounds, plant nutrients are released in available forms for root uptake and the cycle begins again. Give three types of microbes that can acts a decomposers ? Explain why farmers usually only use a field for 2 years on one year off when growing crops like corn, wheat and potatoes ? Explain why animal waste or manure is spread back onto field just prior to planting in the spring ? Recycling of micronutrients dead organic matter soil nutrients Potassium Nitrates decomposers Soil nutrients Plant growth Plant or animal biomass Plant or animal death C5.7 a Phosphates Carbon Key concepts
Look at the photograph and information and answer all the questions: The carbon cycle describes how carbon found in organic molecules, fossil fuels like coal and oil or in the air as carbon dioxide is cycled over time. Because humans are extracting fossil fuels like coal and oil from underground and then combusting them we are currently adding 3 billions tonnes of carbon (in CO 2 ) to the atmosphere every year. This is slowly warming our planet because the carbon dioxide molecules traps infra red energy from the sun. This effect is known as global warming. The carbon cycle Look at the diagram opposite left, it shows the carbon cycle. Which activity adds most carbon dioxide to the atmosphere which already contains 775 billion tonnes of carbon dioxide ? List three changes to the Word’s climate if atmospheric carbon dioxide continues to rise at the current rate of 3 billions tons a year ? C5.7 b Key concepts
Look at the photograph and information and answer all the questions: When hydrocarbons like methane are burnt, carbon dioxide is produced as a by product. We are adding about 3 billion tonnes of CO 2 every year to our atmosphere. This gas traps the sun's heat and has led to global warming. Coal-burning power stations and the millions of cars, lorries and planes are the largest source of carbon dioxide pollution -- they produce about 2.5 billion tonnes per year. Name three effects of global warming, for example the polar ice caps melting ? How could we reduce our carbon footprint…meaning the amount of carbon dioxide we release into the atmosphere every year ? Look at the graph left…do you think that rising amounts of CO 2 in the atmosphere is linked to increasing average global temperatures over the last 150 years ? O 2 CH 4 H 2 O CO 2 Key Substrates Products CH 4 + 2O 2 CO 2 + 2H 2 O C5.7 c Key concepts
Look at the photograph and information and answer all the questions: The nitrogen cycle describes how nitrogen found in organic molecules, air and as nitrates in the soil is cycled over time. Nitrogen is the most common element in the atmosphere yet plants cannot absorb it in the form of nitrogen gas. It must be in the form of soluble nitrates. Nitrogen in the form of nitrates is essential when plants make proteins. Soil with low levels of nitrates give rise to poor crops. Lightning causes some nitrogen to enter the lithosphere but not much. The main way is through nitrogen fixing bacteria. The carbon cycle C5.7 d Nitrogen fixing bacteria that turn nitrogen gas into nitrates live in the roots of some plants and provide them with nitrogen. Suggest what the bacteria get in return in this symbiotic relationship ? Look at the diagram above and suggest a) two ways nitrogen is returned to the soil and b) why do farmers spread animal waste (manure) onto field where they grow crops like wheat and corn ? Key concepts
C5.7 Plenary Lesson summary: nitrogen cycle bacteria carbon Friday 21 October 2011 Scrubbers are a type of air pollution control devices that can be used to remove some carbon particulates and/or gases like sulphur dioxide (SO 2 ) and carbon dioxide (CO 2 ) from industrial exhaust streams. By removing these gases, they can be used to reduce our impact on the environment. How Science Works: Research into how we extract and use metals from metal ores found in the lithosphere ? Preparing for the next lesson: Elements such as ___________ move between the spheres constantly. Two examples of this are the ___________ cycle and the carbon ________. Carbon dioxide is produced when we burn fossil fuels. Nitrogen is needed by plants to grow and is provided by __________ in their roots. Decide whether the following statements are true or false : False True 3: Bacteria found on certain plants roots can fix nitrogen for plants to use ? False True 2: Nitrogen is used by living things to make carbohydrates ? False True 1: Carbon dioxide is the only gas contributing to the greenhouse effect ?
C5.8 Metals from the lithosphere (part one) Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand that metals like iron are extract from their iron metal ores like haematite </li></ul><ul><li>Understand that that the way metals are extracted form their ore depends on their reactivity. </li></ul><ul><li>Understand that reactive metals are extracted from their ore using electrolysis </li></ul>We will focus on. Friday 21 October 2011 First activity: Match the metals with their ores: Ores: Haematite, bauxite, rock salt and malachite Metals: Copper, iron, sodium and aluminium. Give one common use for each metal ? Literacy: Metals, metal ores. Extraction, roasting, smelting, electrolysis, blast furnace, ore, oxide, reactive metals, gold, iron, silver, copper, zinc, magnesium, sodium and aluminium Numeracy: Approximately 161,000 tonnes of gold have been mined in all of history. The current market price for gold bullion is a staggering $1200 per ounce (28 grams). The largest ever gold nugget found weigh almost 200 kg and was worth about £2,000,000. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on being self managers by evaluating your own work and managing your own behaviour. Team workers Effective participators Self managers
Metals from the lithosphere (part one) Extension questions: 1: What is a metal ore and name three ore found in the lithosphere ? 2: Name five metals and give two uses for each metal for example copper used in wiring and water pipes ? 3: Explain why gold and silver were first discovered many thousands of years ago ? 4: Why might it be harder to remove more reactive metals form their ores and why was aluminium only discover after Faraday discover electricity ? Know this: a: Know that metals are extracted form their ore which are mined form the lithosphere. b: Know that un-reactive metals like silver and gold can be found in their pure form. Friday 21 October 2011 Introduction: Apart form gold and silver, most metals are not found simply in elemental form. Metals such as sodium, lithium, iron, magnesium, potassium, aluminium etc. all form compounds within the lithosphere. These are called metal ores which have none f the physical properties of the pure metal. We therefore have extract the metal form its ore using roasting, smelting with carbon and electrolysis. Extracting metals form their ores can be costly and polluting. We first decide how it should be done and if there is enough ore to make it worthwhile. Secondly, how much energy will it use and what impact will digging it up have on the environment. C5.8
Look at the photograph and information and answer all the questions: The largest group of elements in the periodic table are the metallic elements. They are found on the left of the table. Metals are usually, hard, malleable, conductive of heat and electricity, sonorous, ductile and have high melting points. Metals have many uses based on their different physical properties. Non metals are usually dull, soft and non conductive of heat and electricity From their symbols name the following metals: a) Ca b) Ti c) Fe d) Na e) Au f) Ag h) Cu i) Zn j) Ni and k) Mg ? In the middle of the table are the transitional metals. Give two uses for a) copper b) iron c) gold and d) mercury ? Explain why a) Bridges are made from iron, b) Planes from aluminium c) Jewellery from gold d) Food cans from tin ? Shiny Sonorous Ductile High melting points Malleable Conductive of electricity Conductive of heat Hard Physical properties of metals The periodic table C5.8 a Key concepts
Look at the photograph and information and answer all the questions: Gold has been mined and extracted from rock deposits and river sediments for many thousands of years. Gold is found in a pure state because it does not combine to form compounds with other non metal elements. Much of the gold mined today is found in South Africa and Brazil. The largest gold nugget was found by Holter. It weighed over 200 kilograms. Its value today would be approximately two million pounds. Give three uses for metals like gold and silver ? Two girls were arguing about the value of their gold rings. The first girl has a 18 ct. ring, the second had a 9 ct. ring...which girls has the more valuable ring and why ? Seams of gold pictured opposite left can often be found in mines deep underground. How would you extract the gold from the rock ? Extracting un - reactive metals Gold C5.8 b Key concepts
Look at the photograph and information and answer all the questions: Moderately reactive metals can be extracted from their compounds or ores using the carbon displacement method. This is also known as smelting. Carbon displaces any metal from its rock ore which is below aluminium in the reactivity series. Other metals that are ‘smelted’ using carbon displacement include lead, zinc, tin and copper. Extracting moderately reactive metals Steel is an alloy made mostly of iron with small amounts of carbon and other metals. Chromium and manganese helps prevent iron from oxidising to form iron oxide or rust. This would weaken any structure made from steel over time. a) Explain why building structures are made from steel rather than pure iron ? b) Give three objects made from steel ? Stainless steel is used to make taps and other objects that come into contact with water. Name three objects made from stainless steel ? Iron C5.8 c Key concepts Fe Iron Cr Chromium W Tungsten C Carbon V Vanadium Mn Manganese
Look at the photograph and information and answer all the questions: Metals have different reactivites when heated in air or when placed in water or acids. Potassium is the most reactive metal, gold the least. Metals like calcium, magnesium and sodium will react in air when heated forming their oxide and will form their salt and liberate hydrogen gas when placed in acids or even cold water. Look at the reactivity series opposite and explain why you would not make a drinks can from calcium, sodium or potassium ? Explain why hot and cold water pipes are made from copper metal and not lead or iron metal ? Explain using the reactivity series why it is rare to find Roman coins that were minted using copper or bronze alloys made from copper and tin ? Metal reactivity Potassium Sodium Calcium Magnesium Aluminium Zinc Iron Lead Copper Silver Gold No reaction in water / acids Most reactive Least reactive C5.8 d Key concepts
C5.8 Plenary Lesson summary: lithosphere gold ore reactive Friday 21 October 2011 Gold is not he most expensive metal, neither is platinum. Because of its rarity, Rhodium is the most expensive metal in the world. It is similar in its appearance to platinum but it used in nuclear reactors to measure radiation levels. Platinum is used to make jewellery and as a catalyst found in catalytic converters How Science Works: Research into how we extract these metals from the ore and can you calculate their formula mass. Preparing for the next lesson: Metal ________ is the way that we find the metals we use everyday in the __________. Most metals are found like this as they are quite __________. ________ is not though and is found as a pure element. Decide whether the following statements are true or false : False True 3: Recycling scrap metal is a cheaper way to get metal False True 2: Silver is found as the ore silvomite ? False True 1: Mining ores causes no harm to the environment ?
C5.9 Metals from the lithosphere (part two) Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand how metal is extracted using carbon displacement from its ore </li></ul><ul><li>Understand how to calculate relative formula mass. </li></ul><ul><li>Understand how to use the periodic table to find relative atomic mass of an element. </li></ul>Friday 21 October 2011 First activity: What are the symbols for following elements and find out their relative atomic mass using the periodic table a) Mg b) Chlorine c) Sodium d) Lithium e) Sulphur f) Iron g) Aluminium and h) Argon. Literacy: Elements, atomic mass, formula mass, ores extraction, carbon displacement, reduction, smelting, blast furnace, formula oxidation, reduction, reducing agent, relative atomic mass and relative formula mass Numeracy: The relative atomic mass of each element is unique. The mass number can be found using the periodic table and is always the larger of two numbers given with any element The lightest elements is hydrogen. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on reflective learners as we will look back at the previous Team workers Effective participators Self managers
C5.9 Metals from the lithosphere (part two) Extension questions: 1: What are the atomic masses of the following elements a) Mg b) Na c) Fe d) O e) S and f) Ne and g) Ag ? 2: List the atoms of elements and their number in the following formulae: a) MgO b) CaCO 3 c) SO 2 d) NaCl e) Fe 2 O 3 f) CO 2 ? 3: What reduces iron as it is extracted form its oxide Fe 2 O 3 ? 4: What problems might you have from producing large amounts of sulphur dioxide when displacing iron form its ore ? 5: Most iron is used to make steel alloys give three uses of steel ? Know this: a: Know how metals are extracted form their ore using the carbon displacement method. b: Know how to calculate formula masses of compounds like iron oxide Fe 2 O 3 . Friday 21 October 2011 Introduction: Some ores are oxides; metals that have reacted with oxygen. When you remove the oxygen to get the metal it is called reduction. A reducing agent is needed to take the oxygen away. The reducing agent will become oxidised as it has gained an electron. A common reducing agent is carbon which is oxidised to carbon monoxide. To work out how much metal you will be able to get from an ore, you need to know the relative atomic mass of each element and then calculate the relative formula mass. You can find the RAM using the periodic table. The relative formula mass is the mass of all the atoms in the compound. For example, the RFM
Key concepts Look at the photograph and information and answer all the questions: Write an equation for the displacement or iron (Fe) from its ore (Fe 2 O 3 ) by carbon monoxide (CO) ? Explain why very high temperature have to be used during the displacement of iron form its ore ? Iron ore is rock rich in iron compounds like iron oxide formula Fe 2 O 3 . Coal is used as a rich source of carbon and as an energy source. They combust coal producing carbon monoxide which then reduces iron oxide to iron. Smelting of iron oxide is done at temperatures of 1700 o C.Pure molten iron is collected in a huge vessel called a pig. Molten iron is then poured into moulds ready for sale . C5.9 a Extracting iron from its ore Mined Haematite Powdered Haematite Displacement of iron from haematite Iron ingots
Key concepts Look at the photograph and information and answer all the questions: First developed around 1496 here in the UK the blast furnace uses carbon form coal to extract iron form its ore. The raw materials: coal, iron ore and limestone are placed into the blast furnace. Air is blasted into the furnace to reach temperatures in excess of 1700 o C, whereby, the iron formed sinks to the bottom and runs into moulds. Carbon acts as a reducing agent displacing iron from its oxide (Fe 2 O 3 ). . Formation of carbon monoxide: 2C+ O 2 2CO (1700 o C) The carbon in coke reacts with oxygen to form carbon monoxide a powerful reducing agent. Reduction of iron oxide 3CO + Fe 2 O 3 2Fe + 3CO 2 The carbon monoxide gas displaces iron from its oxide producing carbon dioxide and molten iron. Extraction of iron using the carbon displacement method C5.9 b The formula of iron oxide is Fe 2 O 3 with a relative formula mass of 156 grams. When displace 156 grams of Fe 2 O 3 will produce 112 grams of iron. Work out what amount of iron would a) 1 kg of Fe 2 O 3 and b) 1000 kg of Fe 2 O 3 produce ? Work out the percentage yield of the carbon displacement method ?
Look at the photograph and information and answer all the questions: The RFM of Fe 2 O 3 is 160. To get this you add together the RAM of each atom in the molecule. There are two iron atoms with a RAM of 56 and three oxygen atoms with a RAM of 16. Therefore 56 + 56 +16 + 16 +16 = 160 grams. Work out the relative formula mass for the following compounds SO 2 , CO 2 , C 2 H 6 & CO R.A.Ms: H = 1, C = 12, N= 14, O = 16, Ca = 20, Al = 27, S = 32 ? The formula of bauxite (aluminium oxide is Al 2 O 3 ) Work out its relative formula mass and what mass of aluminium would 100 kg of Al 2 O 3 yield ? Fe 2 O 3 Fe Fe O O O 56 56 16 16 16 56 + 56 16 +16 + 16 = 160g Once you understand the relative atomic mass of atoms, you can also work out the relative formula mass of any molecule or compound. Using its formula, all you have to do is add up the masses of each type of atom present in the molecule. For example ,the relative formula mass for a molecule of oxygen is twice 16 g, therefore 32 g (O 2 : 2 x 16 = 32 g) The formula of sodium chloride is NaCl. Work out a) the relative formula mass and b) the percentage by mass of Na in NaCl C5.9 c Understanding formulae Key concepts
Look at the photograph and information and answer all the questions: Once you understand the relative atomic mass of atoms, you can also work out the relative mass of any molecule or compound. Using its formula, all you have to do is add up the masses of each type of atom present in the molecule: e.g. The relative formula mass of carbon dioxide (CO 2 ) is 44 (CO 2 : 12 + 2 x 16 = 44 g) Work out the relative formula mass for the following compounds SO 2 , CO 2 & C 2 H 6 ? R.A.Ms: H = 1, C = 12, N= 14, O = 16, Ca = 20, Al = 27, S = 32? C5.9 d Methane Water Ethene Ammonia CH 4 H 2 O C 2 H 4 NH 3 12 + 4 x 1 = 16g 16 + 2 x 1 = 18g 2 x 12 + 4 x 1 = 28g 14 + 3 x 1 = 17g What would be the RFM of Mg(OH) 2 (magnesium hydroxide) be ? (RAM Mg = 24, O = 16 and H =2) Chlorine has a RAM of 35.5 What is the formula for magnesium chloride and what would its RFM be ? Understanding relative formula mass Key concepts 12 16 1 1 1 1 1 1 12 1 1 1 1 12 1 1 1 14
C5.9 Plenary Lesson summary: oxygen RFM reduction RAM Friday 21 October 2011 Mass spectrometry (MS) is an analytical technique for the determination of the elemental composition of a small sample of an unknown compound. When an unknown sample is run through a mass spec, different atoms will be detected based on their unique mass relative to one another. Mass spec is also used for finding out the chemical structures of molecules. How Science Works: Research into how reactive metals like aluminium and titanium are extracted using electrolysis. Preparing for the next lesson: To get the metal from a metal oxide ore, you need to remove the ________. To do this you need a reducing agent which will accept the oxygen from the metal. This is a __________ of the metal ore. Using the periodic table you can find out the ________. For a molecule, you can calculate the ________ from each atom. Decide whether the following statements are true or false : False True 3: A formula tells us the number and nature of atoms present in a compound ? False True 2: The relative formula mass of hydrogen is 2 and its symbol is Hy ? False True 1: The relative atomic mass of helium is 4 and its symbol is He ?
C5.10 Metals from the lithosphere (part three) Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand that reactive metals like aluminium and titanium cannot be extracted using the carbon displacement method </li></ul><ul><li>Understand that reactive metals are extracted and separated form their ores using electrolysis. </li></ul>Friday 21 October 2011 First activity: Aluminium is used in drinks can, planes and other products. Why is aluminium often preferred when compared to steel (alloy of iron) Give three reasons based on its chemical or physical properties ? Literacy: Metal extraction, reactive metals, electrolysis, electrode, electrolyte, ions, carbon, anode, cathode, aluminium and bauxite. Numeracy: The formula of Aluminium oxide is Al 2 O 3 . Aluminium ions have a charge of +3 and oxygen ions have a charge of -2. The overall charge on the Al 2 O 3 compound is zero since (2 x +3) + (3 x -2) = 0. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on independent enquirers who can find out information using their own initiative. Team workers Effective participators Self managers
C5.10 Metals from the lithosphere (part three) Extension questions: 1: Give three uses for a) aluminium and b) titanium ? 2: Why can’t reactive metals above carbon in the reactivity series be smelted or reduced form their ores using a blast furnace ? 3: In an electrolytic cell, what do you called the negative electrode and what do you call the positive electrode ? 4: Which of the following ions will travel to the cathode a) Na+ b) Fe 3+ c) O 2- and d) C l- ? 5: What would be the products if LiF was electrolysed Know this: a: Know that reactive metals like aluminium must be extracted using electrolysis. b: Know that the ore of aluminium is called bauxite and that during the electrolysis of bauxite it first has to be melted forming electrolyte. Friday 21 October 2011 Introduction: Some metals are so reactive that they don’t want to let go of any oxygen they have reacted with. We therefore use electrolysis to remove it. Electrolysis of aluminium takes place a steel tank lined by carbon. Electrolysis turns ions back into atoms as positive metal ions are attracted to the negative electrode (cathode) and gain an electron. Negative non metal ions are attracted to the positive electrode and lose an electron. Once this has happened, the atoms have reformed and they can be collected. For Aluminium Oxide, this will produced pure aluminium and oxygen gas.
Look at the photograph and information and answer all the questions: Reactive metals like aluminium are extracted from their ores using electricity. Displacement from their ores using carbon smelting will not work. A process called electrolysis separates the metal from its ore. Firstly, the ore is made molten using heat energy. A current is then passed through the molten ore. Both steps use a lot of energy, making these metals very expensive Explain why any metal that require extraction by electrolysis was not discover before Faraday’s discovery of electricity ? Give three objects made from aluminium ? Aluminium metal although more reactive than iron has a protective oxide layer that stops it reacting with water, oxygen or acid...explain why this makes it an ideal material to make drink cans from ? Extracting reactive metals Aluminium Aluminium electrolysis C5.10 a Key concepts
Key concepts Look at the photograph and information and answer all the questions: Explain a) what is happening at the cathode and b) the cathode ? Although aluminium is more abundant when compared to iron in the Earth’s lithosphere...explain why iron is cheaper than aluminium ? During electrolysis, the aluminium ions gain three electrons forming aluminium metal and the oxide ions lose their two electrons forming molecular oxygen. The energy required to transform ions back into their atoms is supplied by electrical energy. Cryolite is added to molten aluminium or bauxite to reduce its melting point. This saves energy and reduces the overall cost. C5.10 b Molten aluminium Molten bauxite ore Electrolysis of bauxite (Al 2 O 3 ) Al 3+ Al 3+ Al e- e- e- e- e- + _ Aluminium Oxygen O 2- e- e- O O O 2- e- e-
C5.10 Plenary Lesson summary: electron electrolysis atoms carbon Friday 21 October 2011 The first electrolysis took place in 1800 - William Nicholson and Johann Ritter decomposed water into its elements hydrogen gas and oxygen gas. The electrolysis of water by electricity generated by renewable technologies will provide the fuel of the future for hydrogen cell powered cars and buses. How Science Works: Research about metals, their physical properties and how metallic bonding is different to ionic and covalent bonds. Preparing for the next lesson: ___________ is the process used to separate highly reactive metal ore. It works by the movement of __________ to change ions into ________. For the electrolysis of aluminium, it is performed in a steel tank which has been lined with __________. Decide whether the following statements are true or false : False True 3: Positive metal ions like Al 3+ and Na + are attracted to the cathode ? False True 2: The negative electrode is called the anode ? False True 1: Aluminium ions have a positive charge and are written as Al 3+
C5.11 Structure and bonding in metals Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand the physical properties of metals like copper, iron and zinc. </li></ul><ul><li>Understand and be able to illustrate what a metal structure looks like. </li></ul><ul><li>Understand how metallic bonding differs to ionic and covalent bonding </li></ul>We will focus on. Friday 21 October 2011 First activity: Explain why the following metals are used a) cooper for copper wiring b) Iron to make steel c) Magnesium to make incendiary devices d) Titanium for bike frames and missile parts e) aluminium to make drinks cans and planes f) Mercury for filing and thermometers and g) gold for rings and coins. Literacy: Metals, shiny, malleable, dense, conductive, sonorous, metallic bonding, metallic structure, ionic, covalent, electrons, lattice, strong and flexible. Numeracy: There are 118 known elements of which 95 are metals (or semi-metals) PLTS Independent enquirers Creative thinkers Reflective learners We will focus on creative thinkers as you with need to use your imagination to imagine the particles in a metal Team workers Effective participators Self managers
C5.11 Structure and bonding in metals Extension questions: 1: What properties does iron have that make it an extremely useful metals and give three uses of iron ? 2: Explain what an alloy is and name three alloys ? 3: Draw a model of metallic bonding showing the free electrons and the lattice of positive ions ? 4: Metallic structure is not ionic or covalent and allows the atoms to move. Explain how this makes metals malleable ? 5: Explain why metals have high melting and boiling points ? Know this: a: Know the physical properties of metals b: Know the metallic structure of metals and that electrons are free to move across a sea of positive nuclei. c: Know that metals are able to conduct electricity due to these free electrons. Friday 21 October 2011 Introduction: Humans have been using metals for thousands of years and our lives now depend on them. Originally, humans only used metals such as gold and iron due to their properties but now we can form alloys (two or more metals mixed together) which has other properties. All metals have the following structure:- Tiny spheres, they are arranged in a regular pattern and are packed closely together in a crystal as a giant structure. When metal atoms bond together they form metallic bonds. These bonds are strong yet flexible. The metal atoms lose their electrons in their outer shell and move freely around the ions. The electrons hold the ions in place tightly but can also conduct electricity as they move freely.
Key concepts Look at the photograph and information and answer all the questions: Metallic elements like iron are used extensively because of their unique physical properties. A physical property describes the metal itself. A typical metal is hard, dense, shiny, malleable and conductive of heat and electricity. Some have more unusual properties, for example iron, cobalt and nickel are magnetic. Also some have a high monetary value like silver, gold and platinum. C5.11 a Properties of metals Dense Sonorus Shiny Conductive of electricity Conductive of heat Malleable Name five metals that are used for their strength. Can you say what they are used for ? Explain why metals have high melting points? Use the words attracted, ions and electrons
Key concepts Look at the photograph and information and answer all the questions: Explain why metals like aluminium, iron and titanium have high melting and boiling points ? Metals form giant structures in which electrons in the outer shells of the metal atom s are free to move. The metallic bond is the force of attraction between these free electrons and metal ions . Metallic bonds are strong, so metals can maintain a regular structure and usually have high melting and boiling points. Because the electrons are free to move, they also conduct electricity. C5.11 b Metallic structure of metals Why is a metal crystal not ionic ? Use the following information to help: - The diagram in the bottom left shows the positive ions and electrons moving around.
C5.11 Plenary Lesson summary: ions malleable metallic electron Friday 21 October 2011 It is claimed the first metal ever mined and used was copper around 8000 years ago. The latest metal to be discovered is called Ununseptium which is made in a laboratory by scientists (as it is not found in nature) by bombarding berkelium with calcium. How Science Works: Research about the lifecycle of metals, in particular aluminium. What is aluminium used for, how is it recycled and why do we recycle metals. Preparing for the next lesson: Metals are strong and _________ (meaning they can have their shape changed without breaking) This is because they have _________ bonds. The metal atoms lose an ___________ from their outer shell and the atoms turn into positive _______. Decide whether the following statements are true or false : False True 3: Metallic bonds are formed due to a sea of free electrons ? False True 2: Steel is an alloy made with iron and copper ? False True 1: Metals break easily when hit hard with a hammer ?
C5.12 The Life Cycle of Metals Decide whether the following statements are true or false: <ul><li>Lesson objectives: </li></ul><ul><li>Understand the lifecycle of an aluminium can </li></ul><ul><li>Understand the impact of mining and disposing metals on the environment </li></ul><ul><li>Understand and explain the benefits of recycling </li></ul>We will focus on. Friday 21 October 2011 First activity: What do you do with a can when you have finished drinking from it? Be honest! What happens to the can if:- a) you throw it on the floor b) you throw it in the normal bin c) you put it in recycling ? Literacy: Mining, aluminium, iron, lead, mercury, nickel, gold, silver, recycling, alumina, bauxite, ingot, waste, ore, recycle, reduce, reuse, waste, landfill and scrap Numeracy: In the United States of America, 100 billion aluminium cans are made a year. That is 100,000,000,000 cans !! Most of these have a very short shelf life and find their way into landfill sites. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on being reflective learners as we will finish the topic in this lesson and need to prepare for the end of unit exam. Team workers Effective participators Self managers
C5.12 The Life Cycle of Metals Extension questions: 1: Think about the manufacture use and dumping of an aluminium can. Describe the processes involved from mining to making the finished drinks can ? 2: Explain why it require less energy to recycle aluminium than mine it and give one way in which we can encourage recycling ? 3: What damage can mining bauxite and then extracting aluminium from the bauxite have on the environment? 4: By choosing the right metal to build cars, we could reduce the use of petrol. What properties of the metal would make a good choice ? Know this: a: Know that metals are a valuable resource and should be recycle after their use b: Know that the life cycle of an aluminium can and that when aluminium ore is purified, it is turned into a powder called alumina. Friday 21 October 2011 Introduction: In order to get the ore we need to extract the metal, we have to mine large holes in the ground. This can destroy habitats for many species as well as destroying the lithosphere. Much waste rock is produced and this is then usually moved to landfill sites. Aluminium is extracted from an ore called bauxite. To get the aluminium from bauxite you have to use electrolysis which uses lots of energy (which will be produced from fossil fuels and therefore increase global warming. To recycle only uses 5% of the energy of electrolysis and does not damage the lithosphere
Key concepts Look at the photograph and information and answer all the questions: Used aluminium is valuable - it is easily and endlessly recycled without quality loss. Aluminium has unique recycling qualities: the quality of aluminium is not impaired by recycling - it can be repeatedly recycled. Aluminium recycling saves energy: re-melting used aluminium saves up to 95% of the energy needed to produce the primary product. C5.12 a Life cycle of an aluminium can Design a poster that could be used to persuade people to recycle more. Use scientific language to do this ? When mining waste is dumped in landfill, it often includes toxic metals such as mercury (bottom right) What possible consequences might this have in the future ?
Look at the photograph and information and answer all the questions: The average family uses over 600 steel cans every year in addition to other products that are scrapped that contain iron. Every tonne of steel packaging recycled makes the following environmental savings:1.5 tonnes of iron ore 0.5 tonnes of coal40% of the water required in production75% of the energy needed to make steel from virgin material1.28 tonnes of solid waste Reduction of air emissions by 86%Reduction of water pollution by 76% C5.12 b Explain a) how the local council and/or government can encourage and help all of us recycle object or product made from iron or steel containing iron and b) which products or objects would you make it compulsory to recycle? Iron and steel alloys containing iron are magnetic. Explain with the aid of a diagram how you could sort scrap iron and steel from other metals like aluminium and copper from normal household rubbish and waste ? Key concepts
Key concepts Look at the photograph and information and answer all the questions: Products themselves do not pollute: it is the factories that made them, the trucks that transported them, the user who uses them and the incinerator that burns them. You need life cycle thinking to understand how products impact on the environment. A life cycle assessment (LCA) allows you to quantify and balance the impacts of products. C5.12 c Life cycle assessment (LCA) of an aluminium can Take an ordinary glass bottle made from sand and limestone. Think about its life cycle. Give a brief account of its manufacture, use and disposal ? Considering there is only 300 years of bauxite in reserve for making aluminium should all aluminium products be recycled ? <ul><li>Impact of the product during its use: </li></ul><ul><li>energy required to transport product to the consumer </li></ul><ul><li>energy required to use product </li></ul><ul><li>energy and chemicals required to maintain it </li></ul><ul><li>Impact of the product being disposed of: </li></ul><ul><li>energy required to transport product to landfill </li></ul><ul><li>energy needed to dispose of the product </li></ul><ul><li>space needed to dispose of the product </li></ul>Cradle Use Grave <ul><li>Manufacture and extraction of iron: </li></ul><ul><li>raw materials required and its transport </li></ul><ul><li>energy used to extract iron from its ore </li></ul><ul><li>Pollution as a result of mining and extraction of iron </li></ul>
C5.12 Plenary Lesson summary: aluminum energy lithosphere landfill Friday 21 October 2011 Drinking cans consists mostly of aluminium, but they are really an alloy. They contain small amounts of other metals as well. These are typically 1% magnesium, 1% manganese, 0.4% iron, 0.2% silicon, and 0.15% copper. Think about that next time you drink your can of fizzy drink ! How Science Works: Revise for the end of module test. Preparing for the next lesson: Recycling is the best way to provide the metal we use everyday. This is because it does not require much _________ to produce it and it does not damage the __________. Thousands of __________ cans are used everyday and it is much better to recycle than put them in ________. Decide whether the following statements are true or false : False True 3: Mining metal ores doesn’t impact on the environment very much False True 2: Aluminium ore is called Bauxite ? False True 1: It is easier to make a new Aluminium rather than recycle ?