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Karteikarten

C2

charlie croxford Englisch 36 Karten

Karten in diesem Stapel (36)

  1. 1Name 5 natural materials (3 from animals, 2 from plants)PLANTS
    - Wood
    - Cotton
    ANIMALS
    -Wool
    Silk
    Leather
  2. 2Name 3 synthetic materials.- Rubber
    - Clothes
    - Paints
  3. 3What is strength and explain the two different types?Strength is how good a material is at resisting a force
    TENSILE STRENGTH: how much a material can resist a pulling force
    COMPRESSION STRENGTH: how much a material can resist a pushing force
  4. 4What is stiffness?Stiffness is how bendy a material is. Steel is very stiff, rubber is not
  5. 5What is hardness?Hardness is how difficult a material is to cut into. Diamond is the hardness material on earth, only diamonds can cut diamonds. Drills also use diamond tips.
  6. 6What is density?Density is a materials mass per unit volume (g/cm3)
    - air is not dense
    - gold is very dense
    - less dense objects float
    - dense objects sink
  7. 7state 3 properties of plasticHard, strong and stiff
    Low density
    mouldable
  8. 8state 3 properties of rubberStrong and soft
    Flexible
    Mouldable
  9. 9state 3 properties of nylon fibresSoft
    Flexible
    Good tensile strength
  10. 10Why is using rubber made in factories better than natural rubber?Factory made rubber is better as you can control its properties
  11. 11What is crude oil made of?Mixture of hydrocarbons
  12. 12Do short chain molecules have a high or lower boiling point?Low
  13. 13What are the two types of bonds in crude oilSTRONG COVALENT BONDS - In between the carbon and hydrogen within each hydrocarbon molecule
    INTERMOLECULAR FORCES OF ATTRACTIONS between different hydrocarbon in the mixture
  14. 14What happens as crude oil is heated?The molecules gain extra energy, this causes them to move more, eventually they will gain enough energy to overcome the intermolecular forces, this causes it to whizz off as a gas
  15. 15Do bigger molecules of crude oil have strong or weak intermolecular forces?Strong
  16. 16Why doesn't crude oil break up into smaller chains?This is because the covalent bonds are strong
  17. 17Why is the boiling point higher is big molecules compared the small ones?This is because more energy is needed to break the bonds
  18. 18What is the process called when crude oil is separated?Fractional distrilation
  19. 19Explain fractional distillationThe mixture of hydrocarbons is separated into groups of different boiling points, these groups are called fractions. Similar fractions have similar boiling points and chain length
  20. 20What are the uses of crude oil?Mostly used as fuels. Makes things like plastics, medicines, fertilisers and food. Less useful hydrocarbons are split apart to make more useful ones like ethene (plastic)
  21. 21What is the process of making new compounds called?Chemical Synthesis
  22. 22What is a monomer?A monomer is a small molecule (short chain length)
  23. 23What is a polymer?A polymer is a big molecule (long chain length)
  24. 24What is polymerisation?Polymerisation is where monomers join together to make a polymer
  25. 25How have polymers replaced natural materials?Polymers such as PVC have replaced wood for window frames. Synthetic fibres like nylon have replaced cotton, wool and silk.
  26. 26Advantages and disadvantages of using polymers instead of natural materials.ADVANTAGES: cheaper, more useful to us and more durable
    DISADVANTAGES: Doesn't look as good, are not comfortable/breatheable
  27. 27Describe the arrange of chains in a dense material.As the material is dense the chains will be closely packed together, therefore spread out in less dense materials
  28. 28What are the chains like when they are held together by weak forces?They are free and tend to slide over each other, this also makes them stretch easy and they have low melting points.
  29. 29What are the chains like when they are held together by strong forces?The chains are held firmly together by cross links (chemical bonds between the polymer chains). High melting points, doesn't stretch easily
  30. 30What does cross linking do to the polymer?They bond the chains making it stiffer, stronger and more heat resistent
  31. 31What do plasticisers do to polymers?They get in between the polymer chains, reducing the forced between them. They make the material soft and easy to shape
  32. 32How does making a polymer more crystalline effect its properties?It straightens out the chains so they are not branched and can fit closer together, making the polymer denser, stronger and have a higher melting point
  33. 33What is nanotechnology?Nanotechnology is the branch of technology dealing with making and use of these nanoparticles
  34. 34Two uses of nanoparticlesUsed in tennis racquets
    Used in sun cream
  35. 35How can nanoparticles be used to modify the properties of materials?Silver nanoparticles are added to polymer fibres used in surgical masks to give it antibacterial properties
  36. 36Health concerns about nanoparticlesNot fully understood. Products containing nanoparticles should be clearly labelled so people can choose whether or not to use them. Needs to investigated properly. If ingested it is thought it could be harmful

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Beschreibung
Karteikarten am C2, erstellt von charlie croxford am 14/05/2014.
Erstellt von
charlie croxford · Mai 2014
Aktualisiert
19 Feb 2016
Aufrufe
14
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