C3 Journey through Time

1. C3 Journey through Time LO: to explain how Britain came into existence as continents, how different climates Britain has experienced and magnetic clues that geologists use to track continents Starter: What are the three main layers of the Earth called?

2. Movement of Change Earth’s outer layer is made of tectonic plates, these plates move because of very slow convection currents in the underlying solid mantle. Movements of the tectonic plates cause oceans to open up slowly between continents in some parts of the world. Plate movements bring continents together with great force, creating mountain ranges. Major volcanic eruptions and earthquakes happen at plate boundaries.

4. Magnetic Past To confirm this scientists used magnetic particles in the rock to track the position of north and south of the Equator. Volcanic lava and sediments contain mineral magnetite. The mineral gets its name from magnetic properties of its crystal. Magnetite can be magnetised in a fixed direction once the rock has cooled enough.

5. The magnetisation line up in the direction of the Earth’s magnetic field at the time. Near the Equator, the magnetisation lies horizontally, nearer to the Poles, the magnetisation is at an angle to the horizontal. By measuring the angle at which crystals are magnetised in rocks, scientists can work out the latitude at which the rock was originally formed. The evidence supported continental drift and development of the theory of plate tectonics.

6. What causes continents to move over the surface of the Earth? Do the observations of magnetic minerals made by the scientists at Imperial College support or conflict with the theory of plate tectonics? Suggest evidence that geologists might look for to test the theory that the northern and southern parts of Britain were once on different continents.

7. Review Learning: LO: to explain how Britain came into existence as continents, how different climates Britain has experienced and magnetic clues that geologists use to track continents

8. Aim • To describe why different rocks provide evidence for plate tectonics Moving rocks7th June Starter Use the picture and labels provided to join up the correct name and part of the Earth’s structure. Once you have completed the task above, write a little bit about each part.

9. Continental drift

10. Ring of fire

11. Plates move in a specific direction.... Which 3 different ways is it possible for the plates to move...with respect to each other?? Look at the arrows.

12. Constructive boundary The recent volcanic ash cloud in Iceland ruined flights for months...

13. Destructive boundary The Nazca plate is moving beneath the South American plate. This pushes the continental crust upwards.

14. Conservative boundary Pacific plate meets the North American plate

15. Modelling sedimentary rock BEAKER This beaker is similar to the one Mr Johnson is holding. WATER Using your common sense, discuss and agree on suitable answers to the questions above. Write your answers in your books SAND

16. Origin of rock Swamp areas Produces chalk (calcium carbonate) which is a compound found in bones and shells. Desert areas Produces coal (mainly carbon). Plant matter can be changed into coal if the conditions prevent it rotting. Warm oceans Produces red sandstone when deposited via wind and rain.

17. Compasses...what’s the point? Which direction does your compass point? Why do all compasses point this way? THIS HAS SOMETHING TO DO WITH THE EARTH AND WHAT THE COMPASS IS MADE OF Is there any way of changing the was a compass points? USE THE MAGNET PROVIDED TO SHOW WHAT HAPPENS WHEN YOU GET NEAR TO IT Are rocks magnetic??

19. Minerals in Britain LO: to explain what geologists can learn by studying can learn by studying rocks and the origins of some of the rocks in Britain Starter: What are the three different types of rock? What are their properties?

20. Clues in Rocks Geologists can use the Earth’s surface to explain the history. Sedimentary rocks contains grains and these can be compared and geologists can tell how the rock was made by the shape and size. Fossils of plants and animals can tell us about the life on the planet at different geological time.

21. British Minerals A chemical industry based on chlorine grew by the River Mersey because underground salt deposits, coal mines and lime stone quarries were nearby. These provided the raw material for making chlorine. The salt, coal and limestone formed at different times and different climates of Britain’s long geological history.

23. Give an example to show how studying a natural process today can tell scientists that processes such as rock formation and mountain building are very slow and take place over millions of years. The chemical industry uses limestone quarried in the Peak District National Park because it is very pure. How do geologists account for the purity of the limestone.

24. Review Learning: LO: to explain what geologists can learn by studying can learn by studying rocks and the origins of some of the rocks in Britain

25. Chemicals from Salt LO: to explain how alkalis were first manufactured on a large scale, why this was such a polluting process and how Parliament began to regulate the chemical industry Starter: complete the following reactions: Hydrochloric acid + sodium hydroxide Nitric acid + sodium hydroxide Potassium carbonate + sulphuric acid

26. Alkali Industry During the 1700s there was a huge demand for alkalis. In 1791, Nicolas Leblanc invented a new process that used chalk or limestone (calcium carbonate), salt (sodium chloride) and coal to make the alkali sodium carboante. In England , Widnes and Runcorn, became the areas where this was produced due to the salt.

27. Leblanc Process The process was highly polluting as solid waste was produced. It also released hydrogen chloride gas into the air. This acidic gas devastated the land around and the solid waste dumped outside the factory slowly gave off a steady stream of toxic hydrogen sulphide gas.

28. Regulations During the 1800s, industries grew and the British public demanded action from Government to control the pollution. Pollution became so bad that in 1863, Parliament passed the first of the Alkali Acts. This Act set up an Alkali Inspectorate who travelled the country to check that at least 95% of acid fumes were removed from the chimneys of chemical factories.

29. They would dissolve the hydrogen chloride in water, this was released into water systems and it killed all the life . In 1874, Henry Deacon invented a way to use the gas. He found that it was possible to oxidise hydrogen chloride to chlorine which can then be used to bleach (bleach paper and textiles). He mixed hydrogen chloride with oxygen and let the two gases flow over a hot crystal. The products produced were chlorine and gas.

30. Review Learning: LO: to explain how alkalis were first manufactured on a large scale, why this was such a polluting process and how Parliament began to regulate the chemical industry

31. Alkalis LO: to explain the used of alkalis, where alkalis used come from and the reaction of neutralisation of acids with alkalis Starter: What is neutralisation?

32. Alkalis • These can be used for; • neutralising acid soils • convert fats and oils to soap • making glass • make chemicals that bind natural dyes to cloth

33. Alum Alum is used for dyeing cloth, it helps the dyes to cling fast to the cloth, so that the colours did not fade too quickly during washing. It was made on the north-east coast of Britain, where rock from the cliffs is rich in aluminium compounds. The rock was roasted in open-air fires for many months. Then they tipped the burnt rock into pits of water and stirred the mixture with long wooden poles.

34. The rock is then settled, the solution of soluble chemicals into lead pans. There they boiled the liquid to get rid of the water and added an alkali to neutralise acids in the solutions. The solution was cooled in wooden casks. Crystals formed and they would be crushed for sale. Potash was one of the alkali used, this is ash of burnt wood. Others were ammonia from stale urine.

35. Reactions • alkalis are soluble in water • when dissolved they raise the pH of water above 7 • they neutralise acids • two very corrosive alkalis are sodium hydroxide and potassium hydroxides • when they neutralise with acids, salt and water are produced Water Salt Alkali Acid + +

36. 1) At which stages of the manufacture of alum were the following process involved? Which processes involved chemical reactions to make new chemicals? Oxidation dissolving Evaporation Neutralisation Crystallisation 2) Stale urine contains 2g of ammonia in 100 cm3 of the liquid. The daily output of a person is about 1500 cm3 of urine. Estimate the mass of ammonia, in tonnes, that could be obtained per person per year (1 tonne = 1000 kg = 100g) 3.75 tonnes of ammonia is needed to make 100 tonnes of alum. Estimate the number of people needed to supply the urine for an alum works producing 100 tonnes of alum per year.

37. Review Learning: LO: to explain the used of alkalis, where alkalis used come from and the reaction of neutralisation of acids with alkalis

38. Ashes of seaweed and lime were mixed with sand to make glass. Plant dyes (alkali) mixed with alum, made the colour stick Ash from burnt plants was used as an alkali source... So was urine from people’s homes pH of soil can be changed by adding alkali (lime)

39. Making lime The lime we use to neutralise soil can be made using calcium carbonate. If we heat up calcium carbonate (CaCO3) in a boiling tube, it decomposes (which means no chemicals react with it, just heat turns it into new products). In this reaction, lime (chemical name is calcium oxide, or CaO) is produced and a gas is given off. To do: Write a word equation for this decomposition reaction. (You’ll need to have a guess at the name for the gas given off) 2) Write a balanced symbol equation for this reaction.

40. Protecting Health and Environment LO: to be able to explain why there is a need to check on the safety of a very large number of chemicals, the European Union’s programme for testing and the problem of persistent harmful chemicals Starter: List as many Chemical Safety Symbols as you can

42. Flammable

44. Toxic

46. Explosive

48. Corrosive

50. Harmful (h) or Irritant (i)