using resources

• What are ceramics primarily made from?

  Ceramics are non-metals with high melting points not made from carbon-based compounds.
• How can clay be described before it is fired?

  Clay is a soft material that can be moulded into different shapes.
• What happens to clay when it is fired at high temperatures?

  It hardens to form a clay ceramic.
• Why is clay ideal for making pottery and bricks?

  Because it can be moulded when wet and then hardened.
• What is another example of a ceramic?


  Glass is another example of a ceramic.
• How is most glass made?

  Most glass is made when it is hot.
• What is borosilicate glass known for?

  Borosilicate glass has a higher melting point.
• What are composites made of?

  Composites are made of one material embedded in another.
• How do the properties of a composite depend on its materials?

  The properties of a composite depend on the properties of the materials it is made from.
• What is fiberglass made of?

  Fiberglass consists of fibres of glass embedded in a polymer plastic matrix.
• What is a characteristic of fiberglass?

  Fiberglass has a low density but is very strong.
• Where is fiberglass commonly used?

  It is used for skis, surfboards, and boats.
• What is a property of pure metals?

  Pure metals often have a regular structure that makes them too soft.
• What is corrosion?

  Corrosion can be very destructive to metals.
• What two elements are needed for iron to rust?

  Both air and water are needed for iron to rust.
• How can you demonstrate that water alone is not enough for rusting?

  By placing an iron nail in water boiled to remove oxygen, it won't rust.
• How can you demonstrate that oxygen alone is not enough for rusting?

  By placing an iron nail in a boiling tube with air and using calcium chloride to absorb water, it won't rust.
• What happens when an iron nail is placed in a boiling tube with both air and water?

  The nail will rust.
• What happens to the mass of a rusted nail?

  The mass of a rusted nail increases due to bonding with oxygen and water molecules.
• What is one way to prevent rusting?

  Coating the iron with a barrier to keep out water and oxygen.
• What is electroplating?

  Electroplating uses electrolysis to reduce metal ions onto an iron electrode.
• When is oiling or greasing used to prevent rusting?

  When moving parts are involved, like on bike chains.
• What is the sacrificial method of preventing rusting?

  It involves placing a more reactive metal with the iron to react with water and oxygen instead of the iron.
• What is galvanization?

  Galvanization involves spraying an object with a coating of zinc.
• What happens if the zinc layer in galvanization is scratched?

  The zinc around the scratch works as a sacrificial metal.
• What are natural resources?

  Natural resources come from the earth, sea, and air without human input.
• What are some examples of natural resources?

  Cotton for clothing and oil for fuel are examples of natural resources.
• Why is recycling metals important?

  Recycling metals uses much less energy than mining and extracting new metals.
• How are metals usually recycled?

  Metals are usually recycled by shaping them and casting them into the shape of a new product.
• What is a life cycle assessment (LCA)?

  A life cycle assessment compares the environmental impacts of products over their lifetime.
• What are the stages of a life cycle assessment for plastic and paper bags?

  • Raw Materials:
  • Plastic Bag: Crude oil
  • Paper Bag: Timber
  • Manufacturing and Packaging:
  • Plastic: Extracted from crude oil, fractional distillation, cracking, polymerisation
  • Paper: Pulped timber processed using lots of energy
  • Using the Product:
  • Plastic: Can be reused
  • Paper: Used for other things as well as shopping
  • Product Disposal:
  • Plastic: Not biodegradable, recyclable, pollutes landfill
  • Paper: Biodegradable, non-toxic, can be recycled
• What is a key finding from life cycle assessments of plastic and paper bags?

  Plastic bags take less energy to make and have a longer lifespan than paper bags.
• What is a limitation of life cycle assessments?

  Some pollutants' effects are harder to quantify than energy use or waste produced.
• Why can life cycle assessments be biased?

  Because they take into account the values of the person carrying out the assessment.
• What are selective life cycle assessments?

  Selective LCAs only show some impacts of a product, potentially biasing results.
• What is the definition of potable water?

  Potable water is water that has been treated or is naturally safe for humans to drink.
• Why do chemists not consider potable water to be pure?

  Because potable water can contain various dissolved substances, unlike pure water which only contains H₂O molecules.
• What are the acceptable pH levels for potable water?

  The pH of potable water should be between 6.5 and 8.5.
• What are some harmful substances that should not be present in potable water?

  Harmful substances include bacteria and other microbes.
• What is fresh water?

  Fresh water is water that doesn't have much dissolved in it.