OCR Chemistry C2

Natural Materials are things which Nature has created with out man made help

Wool, Wood and cotton are all natural things as man did not assist with its creation.

Synthetic Materials for example China and Plastic are things that man has changed. Man has changed the properties of the material and has turned into something else.

Melting Point: The point when a substance turns into a liquid

Strength: How much force it needs to break

Stiffness: How brittle an object is

Hardness: how difficult to scratch or cut an object

Density: Mass divided Volume of an object

Mean = Add all but outlyers divided by number

Range = highest minus the lowest

Repeat = As you might get an outlyer, exclude outlyers

Range = Helps us see difference in different charts. 

Qualitative = looks at good data when

Quantitative = looks at lots of data

Correlation = looks at the relationship 

Polymer = lots of monomers, makes up synthetic materials when a reaction takes place.  This reaction is called polymerisation.

Monomer = One bead of the polymer chain.

Straight = strong = HDPE

Branch = weak = LDPE

1.  Length

0000000 (stronger) 000 (weaker)

2.  Chrystalinity

000000000                                     0000000

00000000 Strong                                  Weak    0000000000

000000

3.  Crosslinks = stronger   bortax (joins 2 branches together)

4. Plasticisers = Cornflour makes stronger (PVC) volcanistaion (for rubber use sulphur)

Recycling

Good:  Allows polymer to live its full life capacity.

Bad:  Uses a lot of energy to melt and sort the materials.

Incinerating: 

Good:  Takes up little space.

Bad:  Gives off pollutants.

Landfill

Good:  Gives off little pollutants

Bad:  Takes up lots of space