W HICH TYPE OF ALLOY BEST USED FOR THE OBJECTS IN THE TABLE BELOW ObjectsWhich type of alloy 1StatueBronze

2Musical instrument Brass 3BridgesSteel 4CutleryStainless steel

5Body of aeroplane Duralamin 6SouvenirsPewter

SYNTHETIC POLYMERS

1. WHAT ARE POLYMERS? A long-chain molecules that consists of repeating units of small molecules called monomers

NATURAL OCCURING POLYMERS SYNTHETIC POLYMERS StarchPolythene ProteinPolypropene CarbohydratesPVC ( Polyviny chloride ) MeatPlastics latex

4. MONOMERS FROM POLYMERS POLYPROPENE POLYVINYL CHLORIDE ( PVC )

5. TYPES OF POLYMERS AND THEIR USES PolythenePerspex Polypropene

PVC Nylon

ADVANTAGES OF USING PLASTICS  Usually cheaper than natural materials  Some polymers such as polyethylene able to conduct electricity and being used to make a new generation of batteries  Some plastics are very strong and used to make fibres

REDUCING POLLUTION OF PLASTICS 3 ways to reduce pollution caused by synthetic polymers  Reuse and Recycle synthetic polymers  Reduce the use of non- biodegradable polymers  Pyrolysis ( burn without oxygen )

GLASS AND CERAMICS

1. W HAT IS THE MAJOR COMPONENT OF GLASS ? Silica or Silicon dioxide, SiO 2

2. NAME THE TYPE OF GLASS FOR THESE GLASSWARE Uses of glassType of glass Cooking utensilsBorosilicate Glass Cheap glassware Soda-lime glass

2. NAME THE TYPE OF GLASS FOR THESE GLASSWARE Uses of glassType of glass GlassesFused glass

Uses of glassType of glass Crystal glass ware Lead crystal glassware Glass panesSoda-lime glass MirrorSoda-lime glass

Optical lensesFused glass Lab apparatusBorosilicate

M ATCH THE PROPERTIES WITH THE GLASS TYPE  CONTAIN BORON OXIDE  ABLE TO STAND HIGH TEMPERATURE AND CHEMICAL REACTION  DOES NOT BREAK EASILY  RESISTANT TO CHEMICAL ATTACK BOROSILICATE GLASS

CONTAINS LEAD OXIDES AND HAS A SHINY SURFACES LEAD CRYSTAL GLASS

VERY EXPENSIVE CAN BE HEATED TO A HIGH TEMPERATURE AND THEN PUT IN COLD WATER WITHOUT CRACKING MAINLY MADE UP OF SILICA FUSED GLASS

EASY TO BE SHAPED BUT CANNOT WITHSTAND HEATBREAKS EASILY SODA LIME GLASS

HIGH REFRACTIVE INDEX LEAD CRYSTAL GLASS

CERAMICS

1. Ceramics are made from clay, which is heated to a very high temperature

2. U SES OF CERAMICS Bricks Mug

3.PROPERTIES OF CERAMICS CONSTRUCTION MATERIAL Hard and brittle Do not corrode TABLEWARE Can withstand high temperature

INSULATORS IN ELECTRICAL EQUIPMENTS AND REFRACTORS Good insulators of electricity and heat

COMPOSITE MATERIALS

1. W HAT IS MEANT BY COMPOSITE MATERIAL Structural material formed by combining 2 or more materials with different substances that have properties superior than those of original components

3) TYPES OF COMPOSITES a) Reinforced concrete i) Concrete consists of a mixture of stones, chips and sand bound together by cement ii) Concrete is strong, but brittle and weak in tension

iii) Steel pillars are strong in tension but are too expensive and can rust iv) Reinforced concrete is concrete reinforced with steel v) Reinforced concrete is stronger and able to support larger loads and do not rust

b) Superconductors i) Superconductors is a substance with almost zero resistance ii) They conduct electricity without loss of electrical energy

iii) Perovsite is a type of ceramic superconductor iv) Superconductors are also used to make magnets which are light but thousand of times stronger than the normal magnet

c) Fibre optic i) Glass cannot conduct electricity or electronic data in form of electron ii) In telecommunication, light has replaced electrons as the transmitter of data

iii) Fibre optic consists of a bundle of glass or plastic thread that are surrounded by data cladding iv) It is able to transmit data, voice and images in a digital format v) Fibre optic is used in medical field as laser in operation and endoscope to examine the internal organs of patients

d) Fibre glass i) Plastics is light and hard but brittle ii) Glass is harder than plastics but breaks easily iii) Fibre optics is obtained by adding plastics, polyester resin to glass

iv) Fibre glass is light, withstand corrosion, can be cast into shapes, impervious to water, not very flammable, not brittle and stronger than steel v) Fibre glass is used in racquets, constriction panels, pipes and water tanks

e) Photochromic glass i) Glass is transparent and not sensitive towards light ii) Photochromic glass contains AgCl or AgBr that causes the glass to go dark in bright light and lighten in the absence of sunlight

iii) It is used to make photo chromic lenses of spectacles and protect our eyes from extreme sunlight

4. T YPES OF COMPOSITES AND THEIR USES UsesTypes of Composites BridgesReinforced concrete Display panelsPhotochromic glass

UsesTypes of Composites Car windshieldsPhotochromic glass Lens in camerasPhotochromic glass High rise building Reinforced concrete Bullet trainsSuperconductor Long distance telephone line Fiber optic Small boatsFiber glass

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