SC26a + b Choosing Materials and Composite Materials

Question 1

examples of clay ceramics? 3

Answer 1

~brick
~porcelain
~china

Question 2

how is glass and clay ceramics similar?

Answer 2

they have similar properties as they both have giant structures

Question 3

why is glass transparent?

Answer 3

atoms are not arranged in a regular pattern so crystals don’t form

Question 4

physical properties of glass and clay ceramics? 6

Answer 4

~durable compounds that change little when heated
~chemically unreactive
~hard and stiff
~brittle
~poor conductors
~high melting point

Question 5

how is glass made?

Answer 5

melting sand and then allowing it to cool and solidify

Question 6

what are polymers?

Answer 6

substances with high average relative formula masses made from monomers

Question 7

properties of polymers?

Answer 7

~can be moulded into complex shapes
~usually strong and chemically unreactive
~poor conductors

Question 8

how can PVC be made softer?

Answer 8

by adding plasticisers

Question 9

an example and use of a polymer?

Answer 9

Rigid PVC - pipes and window frames

Question 10

properties of metals? 5

Answer 10

~strong and hard
~shiny
~high melting points
~good conductors
~malleable

Question 11

alloys?

Answer 11

different metals mixed together

Question 12

why are alloys better?

Answer 12

often stronger

Question 13

why are metals electroplated?

Answer 13

~improve appearance
~improve resistance to corrosion

Question 14

why are bathroom taps usually made from a metal electroplated with chromium?

Answer 14

~improves appearance
~chromium is resistant to corrosion

Question 15

why are bathroom mirrors made from a sheet of glass coated on the back with a layer of aluminium?

Answer 15

~aluminium provides a shiny layer which reflects light evenly
~glass is transparent so the shiny layer can be seen through it

Question 16

composite materials?

Answer 16

mixture of two or more materials combined to produce a material with improved properties

Question 17

can individual materials be separated from a composite material?

Answer 17

yes, using physical separation methods

Question 18

what do many composite materials consist of?

Answer 18

reinforcement and matrix

Question 19

properties of composite materials?

Answer 19

they have the same properties as the individual materials

Question 20

concrete properties?

Answer 20

strong n compression but weak in tension

Question 21

what is steel reinforced concrete?

Answer 21

framework of steel bars with concrete poured in and around it

Question 22

why use steel reinforced concrete?

Answer 22

~it is strong in tension and compression
~less dense and cheaper than steal alone