Conserving materials

Question 1

how is glass made?

Answer 1

(soda, limestone, sand make soda lime glass
this is heated lots and as it cools down makes solid glass
glass has a disordered structure

Question 2

what are ceramics used to make?

Answer 2

bricks
tiles
crockery

Question 3

how is clay made?

Answer 3

clay is a mixture of alluminium, potassium and non metals (silicon and oxygen)

this wet clay is moulded and heated so water is driven out forming a strong regular, giant dry structure

Question 4

what are composite materials?

Answer 4

materials made from two or more different materials wich give improved properties for specific uses

they often have a binder (matrix) which surrounds fibres or fragments of another material (the reinforcement)

glass-ceramic- bothe brittle but when combined get a toughened material

Question 5

what are thermosoftening plastics?

Answer 5

plastics that when heated they soften and can be mpulded into a shape

Question 6

what are thermosetting plastics?

Answer 6

plastics that are only soft when first made and can be moulded they then set hard

Question 7

why do thermosoftening and thermosetting plastics act differently?

Answer 7

thermosoftening plastics have weak intermolecular foces between polymer strands that are easily overcome
whereas thermosetting plastics have crosslinks between strands meaning the structure can not be easily interupted by heat

Question 8

what is corrosion?

Answer 8

corrosion is a chemical reacton between a metal and its environment (water and air)

Question 9

what is the equation for corrosion?

Answer 9

iron + oxygen + water ——–> hydrated iron oxide

Question 10

how can you prevent rusting?

Answer 10

-coat iron in paint
-coat iron in oil and grease
-coat iron in plastic
-coat iron in a less rective metal
-coat iron in a more reactive metal (galvanising) (sacrificial protection)

Question 11

what happens if the coating on the iron is breached?

Answer 11

water and air can get to it and rust will spread quickly

Question 12

what makes rust brittle?

Answer 12

air spaces in it

Question 13

why are more reactive metals strong reducing agents?

Answer 13

they easliy form positive ions by giving away electrons so another atom is reduced while it is oxidised rendering it more unreactive