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*,of 49,Boardworks Ltd 2006,Click to edit Master title style,Boardworks Ltd 2006,*,of 49,Boardworks Ltd 2006,*,of 49,Boardworks Ltd 2006,*,of 49,Boardworks Ltd 2006,*,of 49,Boardworks Ltd 2006,*,of 49,How many different uses of metal can you spot?,What are metals used for?,Why are metals important?,Metals are a highly valuable group of materials,used for hundreds of products and produced in huge quantities.,35,500,000 tons of,aluminium,were produced in 2019.,The production of,copper,increased by more than,20 times in the 20,th,century.,Gold,is worth more than 10,000 per kilogram.,Metals have played a vital role in human development.Periods of civilization are even classified by the metals that were used during those times,such as the,Iron Age,.,Using metals,Uses of metals activity,What else can metals be used for?,It is easy to find products made from metals,but there are other uses of metals that are less obvious.,Compounds containing metals have many uses.For example,metal compounds are used to colour materials including stained glass and even make-up!,Metals are used as catalysts to speed up reactions.,Nickel,is used as a catalyst to make margarine.,Platinum,is used in catalytic converters in car exhausts to clean up fumes and reduce pollution.,Can you find any other uses of metals?,What decides what metals are used for?,It is not only the properties of a metal that determines its use.,What other factors might determine how metals are used?,For example,aluminium only became a commonly used metal in the late 19,th,century as better extraction methods made it cheaper.,For example,silver is a better conductor than copper but it is too expensive to be used for electric wires.,Cost,.A metal may have the best properties for a job but it might be too expensive.,Extraction method,.This can greatly affect the price and availability of a metal.,What are the properties of different metals?,Do all metals behave in the same way?,What are the general properties of most metals?,solid at room temperature,Why do metals have these particular properties?,Typical properties of metals,high melting point,good conductors of electricity and heat,malleable:they can be shaped,ductile:they can be drawn into wires,strong,dense,What is the structure of metals?,sea of electrons,metal ions,The atoms in a pure metal are in tightly-packed layers,which form,a regular,lattice,structure.,The outer electrons of the metal atoms separate from the atoms,and create a,sea of electrons,.,These electrons are,delocalized,and so are free to move through,the whole structure.,The metal atoms become positively charged ions and are attracted to the sea of electrons.This attraction is called,metallic bonding,.,Electrons and metallic bonding,How does the sea of electrons affect the properties of metals?,Why do metals have high melting points?,Metals often have high melting points and boiling points.Gold,for example,has a melting point of 1064,C and a boiling point of 2807 C.,The properties of metals are related to their structure.,In metal extraction and other industrial processes,furnaces often run continuously to maintain the high temperatures needed to work with molten metals.,This property is due to the strong attraction between the positively-charged metal ions and the sea of electrons.,How do metals conduct heat and electricity?,Delocalized electrons in metallic bonding allow metals to conduct heat and electricity.,This makes heat transfer in metals very efficient.,Delocalized electrons also conduct electricity through metals in a similar way.,For example,when a metal is heated,the delocalized electrons gain kinetic energy.,These electrons then move faster and so transfer the gained energy throughout the metal.,heat,Metals are usually strong,not brittle.When a metal is hit,the layers of metal ions are able to slide over each other,and so the structure does not shatter.,Why are metals strong?,The metallic bonds do not break because the delocalized electrons are free to move throughout the structure.,metal after it is hit,force,force,This also explains why metals are malleable(easy to shape)and ductile(can be drawn into wires).,metal before it is hit,Metallic bonding,Corrosion is the gradual destruction of a metal due to reactions with other chemicals in its environment.,Over time,corrosion changes the appearance of the metal as it breaks down and it becomes weaker.,What is corrosion?,Coating the surface of a metal with paint and certain chemicals can protect it from corrosion.,What happens if the protective coating becomes damaged?,Corrosion can seriously damage metallic objects and structures.,Metals behave differently when exposed to the environment.,Items made from gold can survive for thousands of years and have even been found in good condition underwater.,Do all metals corrode?,In many cultures,gold is considered a precious metal and is used to make sacred and decorative objects.,Gold is an unreactive metal and does not corrode easily.,In gener
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