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F.3 Chemistry. Metal. Periodic Table. Metallic Bonding. Content. Uses of Metal. Metallic Bonding. Extraction of metal. Conservation. Increasing Non-metallic Character. Decreasing Non-metallic Character. The Periodic Table. Melting point and boiling point decrease down the group.
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F.3 Chemistry Metal
Periodic Table • MetallicBonding Content • Uses of Metal Metallic Bonding • Extractionof metal • Conservation
Increasing Non-metallic Character Decreasing Non-metallic Character The Periodic Table
Melting point and boiling point decrease down the group. Reactivity of Group I elements increases down the group. Group I ---- Alkali Metal Atoms of alkali metal. Form ions carrying one positive charge (for example, Li+, Na+, K+). All react with non-metals to form compounds. These compounds are all white, crystalline and soluble in water.
Group II ---- Alkaline Earth Metal Reactivity of Group II elements increases down the group. All react with non-metals to form salts. Atoms of alkaline metals form ions carrying two positive charges (for example, Be2+, Mg2+, and Ca2+ ). Melting point and boiling point decreases down the group similar to the properties of Group I.
e- e- e- e- e- e- e- e- e- e- e- Metallic Bonding sea of electrons Metal atoms are joined to each other in a giant metallic structure by metallic bond. Metallic bond is a type of bonding between the negatively charged electrons and positively charged metal ions. e-
Metals generally havehigh densitiesdue to close packing of their atoms. Density metal
Melting Point & Boiling Point Metals have high melting and boiling point due to the giant ionic lattice and strong metallic bond.
Electrical Conductivity Light bulb Metals aregood conductors of electricitydue to the movement ofmobile electronsin a metal. Metal part of a screw
Thermal Conductivity Metal Rod Do not touch a red hot metal rod with bare hand because metal is a good conductor of heat.
Strength Gate Bridge Most metals have high strength. They can support a heavy load without breaking.
Force exerted Malleability & Ductility Metal can be hammered into thin sheet without breaking Metals are malleable and ductile since the non-directional metallic bond still hold the metal atoms together.
Uses of Common Metals When choosing a metal for a particular use, we need to consider the following questions: Does the metal need to be ……. Strong? Light? Shiny? Resist corrosion? Cheap?
Best of the Best... Au Copper Gold Cu Al Aluminium The metal which is the best conductor of heat is Metal with the best corrosion resistance The most abundant metal found in the Earth’s crust And With the lowest density of all is
Metal with the highest tensile strength is Iron The best electrical conductor is … and as well. Silver Copper Cu Metal withthe lowest melting point is Tin Sn
Uses of Metals • Jewellery and decorations are made of gold or silver due to their attractive appearances. • Pipe and sheet for roofing can be made of lead. • Copperfor making electrical wire in the house.
Gate at the front door is made ofiron. • Food cans are plated withtin. • The body of a ship is protected by attachingmagnesiumorzincblocks to it. • Light bulb filament is made oftungsten.
Potassium and calcium are used in manufacturing fertilizers. Silver bromideis used in film developing
Uses of metals Summary Uses of Aluminium
Uses of metals Summary Uses of Copper
Uses of metals Summary Uses of Gold
Uses of metals Summary Uses of Iron
Uses of metals Summary Uses of Lead
Uses of metals Summary Uses of Silver
Uses of metals Summary Uses of Tin
Uses of metals Summary Uses of Titanium
Uses of metals Summary Uses of Tungsten
Uses of metals Summary Uses of Zinc
Check it out! Decide which metal(s) is/are most suitable for making a) high speed drill head b) window frame c) saucepan. Ans: a) iron b) aluminium c) copper
Extraction of Metals • Only a few metals such as gold (Au) and platinum(Pt) exist as free elements in the Earth. Gold
Other metals occur as compounds in the Earth’s crust. For example: Iron, Zinc, Aluminium, Copper, Tin, Lead and Silver. Ag Fe Hg Pb • Rocks that contain metal-containing compounds are called mineral ores.. Metals are extracted from these mineral ores. Metal Ores
Metal Extraction • Metal can be extracted from the ores by • (i)__________ the ore alone, • (ii) __________ with carbon and • (iii)by using ____________. heating heating electricity
Conservation of Metals ------- The Three ‘R’s Recycling Replacing Reusing
Use of Recycling Bag Conservation of Metals ------- Recycling Supply of metals in the Earth’s crust is limited, while the demand for metals is kept increasing. Recycling is an effective way of conserving metals as the cost is reduced and energy is saved. It also minimizethe environmental problems arose in metal extraction and waste disposal.
Reusing Old metal articles can be used again, it is a waste to throw it away. e.g. Aluminium foil
Replacing New materials have already been used to replace some metals. For instance, copper pipes can be replaced by plastics ---- PVCand telephone wires made ofoptical fibresare commonly used.
Importance of Recycling - save metal resources - save energy - save other resources such as water - Environmental problems, such as waste disposal and mining problems, can be reduced Mining process
Problems in Recycling -the cost of collecting the scrap metals - the cost of transporting scrap metals to the recycling plant - the cost of melting and purifying metal - the cost of disposing the waste from the recycling process
Check it out! 1) Metal resources are limited, what should people do in order to make the resources last longer? Ans: By conservation of metal resources: recycling, reusing and replacing metals with other materials.
Check it out! 2)Refer to Fig. 9.3 on your textbook, why will the resource of Al last longer than other metals? . Ans: It is because Al is the most abundant metal on the earth crust.
Check it out! 3) Which of the following Al articles is easier to recycle - Al drink can or an aircraft made of Al alloy (a mixture of metals)? Explain your answer. . Ans: Drink can is easier to recycle because it only contains a metal, while the aircraft is made up of more than 1 metal, this require separation of metals before recycling process can take place.