4th Sep '25

Schemes of Work

C2
- C2.4
  - Lesson 01 - How has the Earth's atmopshere changed since its formation? Lesson Plan Lesson Title
    - Students to recall current composition of the earths atmosphere: about four-fifths (approximately 80 %) nitrogen, about one-fifth (approximately 20 %) oxygen and small proportions of various other gases, including carbon dioxide, water vapour and noble gases.
      - Suggested Activity:
        Draw accurate pie charts for the composition of the atmosphere.
    - Students should be able to, given appropriate information, interpret
      evidence and evaluate different theories about the Earth's early
      atmosphere.
      - Suggested Activity:
        Earths early atmosphere:
        https://www.youtube.com/watch?v=Gyn754vw8ZQ
    - One theory suggests that during the first billion years of the Earth's
      existence there was intense volcanic activity that released gases that
      formed the early atmosphere and water vapour that condensed to
      form the oceans. At the start of this period the Earth's atmosphere
      may have been like the atmospheres of Mars and Venus today,
      consisting of mainly carbon dioxide with little or no oxygen gas.
      - Suggested Activity:
        Evolution of the Earth's atmosphere:
        https://www.youtube.com/watch?v=gwGeH9O8Rx4
    - Volcanoes also produced nitrogen which gradually built up in the
      atmosphere and there may have been small proportions of methane
      and ammonia.
    - When the oceans formed carbon dioxide dissolved in the water and
      carbonates were precipitated producing sediments, reducing the
      amount of carbon dioxide in the atmosphere. No knowledge of other
      theories is required.
    - Algae and plants produced the oxygen that is now in the atmosphere
      by photosynthesis, which can be represented by the equation.
      - Suggested Activity:
        Demo: Aquatic plants (eg Elodea) producing oxygen in daylight.
        (Interleaving opportunity to require practical with colours and ruler for intensity).
        Equipment Required:
        DEMO:
        Aquatic plant in water with high carbonate concentration.
        Lamp
        different coloured acetates
        meter ruler
    - Algae first produced oxygen about 2.7 billion years ago and soon after
      this oxygen appeared in the atmosphere. Over the next billion years
      plants evolved and the percentage of oxygen gradually increased to a
      level that enabled animals to evolve.
    - Algae and plants decreased the percentage of carbon dioxide in the atmosphere by photosynthesis.
    - Carbon dioxide was also decreased by the formation of sedimentary rocks and fossil fuels that contain carbon.
    - Students should be able to describe the main changes in the atmosphere over time and some of the likely causes of these changes
      - Suggested Activity:
        2 x Demos to show the reactions occurring in a volcano
        
        EW: Describe the theory of the evolution of the Earth’s early atmosphere.
        or
        Explain why the composition of the atmosphere has changed over billions of years.
        or
        Compare the Earth’s atmosphere to that of Mars and Venus.
        Equipment Required:
        Demo 1:
        1. Cover the desk with foil and complete the demonstration behind a safety
        screen. Wear eye protection.
        2. Spread approximately 5g of Potassium Permanganate (VII) on to the
        metal dish.
        3. Pour over approximately 10ml of glycerol, stand back and observe.
    - Students should be able to describe and explain the formation of deposits of limestone, coal, crude oil and natural gas.
  - Lesson 02 - How does carbon dioxide help sustain earths climate? Lesson Plan Lesson Title
    - Oreenhouse gases in the atmosphere maintain temperatures on Earth high enough to support life. Water vapour, carbon dioxide and methane are greenhouse gases.
      - Suggested Activity:
        Describe the effect of greenhouse gases on wavelength.
    - Students should be able to describe the greenhouse effect in terms of the interaction of short and long wavelength radiation with matter.
    - Some human activities increase the amounts of greenhouse gases in the atmosphere. These include:
      - carbon dioxide
      - methane.
      Students should be able to recall two human activities that increase the amounts of each of the greenhouse gases carbon dioxide and methane.
    - Based on peer-reviewed evidence, many scientists believe that human activities will cause the temperature of the Earth's atmosphere to increase at the surface and that this will result in global climate change. - b
    - There are difficulties in such complex systems as global climate change. This leads to simplified models, speculation and opinions presented in the media that may be based on only parts of the evidence and which may be biased.
    - Students should be able to evaluate the quality of evidence in a report about global climate change given appropriate information
    - Students should be able to describe uncertainties in the evidence base
    - Students should be able to recognise the importance of peer review of results and of communicating results to a wide range of audiences.
      - Suggested Activity:
        Use the internet to obtain data for concentrations of greenhouse gases.
        Evaluate the reliability of the data available on the internet.
        
        Research the process of peer review in reporting results/data.
  - Lesson 03 - How is human activity resulting in climate change? Lesson Plan Lesson Title
    - An increase in average global temperature is a major cause of climate change.
      There are several potential effects of global climate changes.
      - Suggested Activity:
        Causes of climate change
        https://www.bbc.com/education/clips/zvw34wx
    - Students should be able to describe briefly four potential effects of global climate change
      - Suggested Activity:
        Greenhouse effect and global warming
        https://www.youtube.com/watch?v=dP-tg4atr5M
        
        Watch the polar ice caps melting and water levels rising but building land with the plasticine, add water and 1 ice cube. Mark water level on the beaker, allow ice to melt and check water level and effects on land.
        Equipment Required:
        Beakers
        plasticine
        (SNK likes pertri dishes)
        Ice
        OHP pens
    - Students should be able to discuss the scale, risk and environmental implications of global climate change.
    - The carbon footprint is the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event.
      - Suggested Activity:
        Describe what a carbon footprint is.
        https://www.youtube.com/watch?v=YB9TCxhjVHo
        
        Calculate students carbon footprints using:
        WWF Footprint Calculator
    - The carbon footprint can be reduced by reducing emissions of carbon dioxide and methane.
    - Students should be able to describe actions to reduce emissions of carbon dioxide and methane
      - Suggested Activity:
        Describe how emissions can be reduced. Suggest the consequences of the reductions on the Earth, atmosphere and everyday life.
    - Students should be able to give reasons why actions may be limited.
  - Lesson 04 - What are the consequences of burning fossil fuels upon the atmopshere? Lesson Plan Lesson Title
    - The combustion of fuels is a major source of atmospheric pollutants.
    - Most fuels, including coal, contain carbon and/or hydrogen and may also contain some sulfur.
      - Suggested Activity:
        What is combustion?
        https://www.youtube.com/watch?v=zEjEqnMBdEM
    - The gases released into the atmosphere when a fuel is burned may include carbon dioxide, water vapour, carbon monoxide, sulfur dioxide and oxides of nitrogen. Solid particles and unburned hydrocarbons may also be released that form particulates in the atmosphere.
      - Suggested Activity:
        Combustion and acid rain
        https://www.youtube.com/watch?v=HE6Y0iEuXMQ
        
        Explain why the following can be produced in combustion:
        • Carbon dioxide
        • Carbon monoxide
        • Soot
        • Water vapour
        • Sulfur dioxide
        • Oxides of nitrogen.
    - Students should be able to describe how carbon monoxide, soot (carbon particles), sulfur dioxide and oxides of nitrogen are produced by burning fuels.
      - Suggested Activity:
        Research task: Study the effects of emisions of:
        • Carbon monoxide on the human body.
        • Sulfur dioxide and oxides of nitrogen on acidity of rain water.
        • Sulfur dioxide and oxides of nitrogen on respiratory system.
        • Particulates on global dimming.
        • Particulates on human health problems.
    - Carbon monoxide is a toxic gas. It is colourless and odourless and so is not easily detected.
      - Suggested Activity:
        Investigate the effects of pollution on rain water using titration. Aim To find out how much alkali is needed to neutralise four samples of rain water.
        enough samples for each group to test one once (20mL per group) and shared results.
        China - pH 1-2
        UK - pH 6
        Greenland pH 7
        Australia - pH 4-5
        
        Phenolphthalein colourless in acidic and pink in alkaline solutions.
        Equipment Required:
        4 samples of "rain water" spiked to have different pH values labelled as:
        China - pH 1-2
        UK - pH 6
        Greenland pH 7
        Australia - pH 4-5
        (in main chem store)
        enough samples for each group to test one once (20mL per group) and shared results.
        
        alkali solution (NaOH) that will neutralise each sample(countries) at a suitable concentration.
        burettes
        conical flasks
        Universal indicator
        pipettes
        20mL measuring cylinders
        NaOH 1molar 50ml per group in burettes
    - Sulfur dioxide and oxides of nitrogen cause respiratory problems in humans and cause acid rain.
    - Particulates cause global dimming and health problems for humans.
    - Students should be able to describe and explain the problems caused by increased amounts of these pollutants in the air.