Arrangement of atoms in metal

Closely packed and in orderly manner.

Meaning of alloy

WHAT IS ALLOY ?

Is a mixture of two or more elements with a certain fixed composition in which the major component is metal

Pure metals are make up of the same type and same size of atoms

The orderly arrangement of atoms make the metal ductile and malleable

Orderly arrangement of atoms in metal enables the layer of atoms to slide on one another when force is applied

Layers of atoms slide over each other

Most pure metals are weak and soft

The properties of pure metal can be improved by making them into alloys

Alloys are stronger,harder and resistant to corrosion,have a better furnish and luster (shining by reflecting light)

ALLOY

Makes pure metal harder and stronger Makes pure metal resistant to corrosion Improves appearance of pure metal

The Arrangement of Atoms in Alloy

The presence of atoms of other metals that are of different size disturb the orderly arrangement of atoms in the metal.This decrease the layer of atoms from sliding.

Thus alloy is stronger and harder than its pure metal

List of Alloys and their Composition

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WHY MAKE ALLOY ?

Brass = Cu +Zn

Bronze = Cu + Sn

Duralumin = Al + Cu + Mg

Steel = Fe +C

Stainless Steel= Fe + Cr + Ni

SYNTHETIC POLYMERS

MEANING OF POLYMER

Polymer : Large molecules make up of many identical repeating sub-units called monomers which are joined together by covalent bonds

Polymerization : A process to join the monomer into chains by repeated linking

NATURAL POLYMER

PROTEIN STARCH

CELLULOSE NATURAL RUBBER

SYNTHETIC POLYMER

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Polythene Polypropene Polyvinylchloride (PVC) Perspex Nylon Terylene

TERYLENE

PERSPEX

NYLON

POLYTHENE

USES OF NATURAL & SYNTHETIC POLYMER IN DAILY LIFE

FUSED GLASSComposition :Silicon dioxide

Properties :High transparency

LIST OF MONOMERS IN THE SYNTHETIC POLYMER&

USES OF SYNTHETIC POLYMER

SYNTHETIC POLYMER MONOMER USESPolythene Ethene Plastic bags,shopping bags,plastic

containers and insulation for electrical wiring

Polypropene Propene Piping,carpets,car batteries , ropes and bottle crates (bekas letak botol)

Polyvinyl chloride (PVC) Chloroethene Artificial leather, water pipes and records (piring hitam)

Perspex Methylmethacrylate Safety glass,reflectors,traffic signs and lens

Terylene Hexane-1, 6-diolBenzene-1, 4-dicarboxylic acid

Clothing,sails and ropes

Nylon Hexane-1, 6-diamineHexane-1, 6-dioic acid

Ropes,clothings and carpets

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GLASS AND CERAMICS

FUSED GLASSComposition :Silicon dioxide

Properties :High transparency

`BOROSILICATE GLASS

Composition :Silicon dioxideSodium oxideCalcium oxideBoron oxide

Properties :High melting pointResistant to heat

Uses :CookwareLab equipment

Soda-lime GLASS

Composition :Silicon dioxideSodium oxideCalcium oxide

Properties ;Low melting pointEasily moulded

Uses

WindowpanesGlass container – bottles and jars

Conducting glass

Coated with a layer of conducting material

Special glasses To make LCD panels

Photochromic glass

Contains silver chloride and copper (I) chloride

To make photochromic lenses which darken when exposed to sunlight

CERAMICS

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LEAD CRYSTAL GLASS

Composition :Silicon dioxideSodium oxideLead (II) oxide

Properties :High densityHigh reflective index

Uses :PrismDecorative glasswwares

Ceramic

Strong Hard but brittle Electrical insulator Resistant to heat

USES OF CERAMICS

Ceramic

Strong Hard but brittle Electrical insulator Resistant to heat