Metals and Non metals

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Presentation Prepared BY- NAME-RAGHAV TREHAN CLASS-VIII-A R.NO.-37 SCIENCE METALS AND NON METALS

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There are about 115 elements known at present. It is difficult to study and describe all the properties of these elements separately.The elements are thus, grouped together.This is called classification of elements. S G a i n * * * * * L o s e * ABILITY TO GAIN AND LOOSE ELECTRONS

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Metal is a chemical element that is a good conductor of both electricity and heat and forms cations and ionic bonds with non-metals . In chemistry , a metal (from Greek "-métallon, "minerals an element , compound , or alloy characterized by high electrical conductivity . In a metal, atoms readily lose electrons to form positive ions ( cations ). Those ions are surrounded by delocalized electrons, which are responsible for the conductivity. METALS

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Nonmetal, or non-metal, is a term used in chemistry when classifying the chemical elements . On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal. (A few elements with intermediate properties are referred to as metalloids ). NON METALS

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MINERAL is a naturally occurring solid chemical substance that is formed through geological processes and that has a characteristic chemical composition , a highly ordered atomic structure , and specific physical properties . By comparison, a rock is an aggregate of minerals and/or mineral oids and does not have a specific chemical composition. Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms. [1] The study of minerals is called mineralogy . MINERALS

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An ore is a type of rock that contains minerals with important elements including metals . The ores are extracted through mining ; these are then refined to extract the valuable element(s). Metal ores are generally oxides , sulfides , silicates , or "native" metals (such as native copper ) that are not commonly concentrated in the Earth 's crust or "noble" metals (not usually forming compounds) such as gold . The ores must be processed to extract the metals of interest from the waste rock and from the ore minerals. ORES

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Concentration of ore-It is the process of removal of impurities from the ore. Reduction-It is the process of the reduction of the metal ore to get the metal in its free state. Refining of metal-The metal obtained by reduction is impure. Refining is the process of purification of metal

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Physical state-all metals are solid at room temperature except mercury which is liquid.Iron,copper,aluminium,gold and silver are some of the examples of metals. PHYSICAL PROPERTIES

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Metals generally have a high density while the non-metals have low density. DENSITY

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Most metals are very hard.They can withstand the high pressure without getting distorted.Non metals are not hard.they are brittle and break into pieces when hammered. HARDNESS

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Metals are malleable,i.e,they can be beaten into thin sheets.Non-metals are non malleable,i.e,they cannot be beaten into thin sheets.They break into pieces on being hammered. Metals have a shining surface.This is known as metallic lustre.Iodine is the only non-metal which has a lustre. LUSTRE MALLEABILITY

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Metals can be drawn into thin wires.This property of metals is known as ductility.Copper,aluminium and iron wires are commonly used in our household for electrical fittings. DUCTILITY

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When a piece of metal is struck with something hard ,a ringing sound is produced.This property of metals is known as sonorosity and metals are said to be sonorous. SONOROSITY

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Metals and non metals differ from each other in their chemical properties also. Let us compare the chemical properties of metals with those of non metals. They are as follows- 1.)Reaction with oxygen 2.)Reaction with water 3.)Reaction with acids 4.)Reaction with alkalies CHEMICAL PROPERTIES

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S ingle-displacement reaction, also called single-replacement reaction, is a type of oxidation-reduction chemical reaction when an element or ion moves out of one compound and into another. (One element is replaced by another in a compound.) This is usually written as A + BX → AX + B This will occur if A is more reactive than B. You can refer to the reactivity series to be sure of this. DISPLACEMENT REACTION

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Noble metals are metals that are resistant to corrosion and oxidation in moist air, unlike most base metals . They tend to be precious, often due to their rarity in the Earth 's crust. The noble metals are considered to be (in order of increasing atomic number ) [1] ruthenium , rhodium , palladium , silver , osmium , iridium , platinum , gold . Other sources include mercury [2] [3] [4] or even rhenium [5] as a noble metal. On the other hand, neither titanium nor niobium nor tantalum are called noble metals despite the fact that they are very resistant to corrosion. NOBLE METALS

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Metals have been an integral part of our daily life since ancient times.They have played an important part in the development of various civilisations.Iron is the most widely used metal.It is used for making cooking vessels,water boilers etc.Aluminium being a very light metal,is used for making aircraft bodies .Silver is used for making jewellery,decoration pieces,tableware etc.Gold and silver wires are used for high electrical contacts in computers. USES OF COMMON METALS

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An alloy is a homogeneous mixture of 2 or more metals or a metal and non metal.Alloys are generally stronger and harder and are resistant to corrosion. 1.)Steel-Construction material,machine parts 2.)Stainless steel-Cooking utensils and cutlery 3.)Brass-Decorative statues nuts and bolts. 4.)Bronze-Coins,medals and statues 5.)German silver-Table ware 6.)Duralumin-Aircraft bodies,automobile parts. 7.)Alnico-magnets 8.)Gun metal-Gum barrels USES OF ALLOYS

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Some of common uses are- 1.)Iodine is used as antiseptic. 2.)Oxygen is essential for all human beings. 3.)Sulphur is used for making fire crackers. 4.)Phosphorous is used in match box industry and fertilizers. USES OF NON METALS

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