MetalsManahil Nadeem8A

IntroductionThis PowerPoint is about the task ‘Does a connection or relationship

exist between the reactivity of a metal and when it was discovered?’ I will show several metals and their discoveries and

information. This is for the Area Of Interaction (AOI) Human Ingenuity. Human Ingenuity is how and what we humans create and its effect. This relates to our unit as we as humans are finding and

using metals, finding out their properties and uses. We are discovering these metals and finding out more about them, as well

as using them.

Does a connection or relationship exist between the reactivity of a

metal and when it was discovered?

Yes, I think that there is a connection between the reactivity of a metal and when it was discovered. Generally, unreactive metals such as gold were discovered earliest about more than 1800 years ago. More reactive metals were discovered at a later date.

This is because the technology needed to extract, isolate and mine these more reactive was not available in those days. Less reactive metals were found more in the past as there was no need for any extra refinement or extraction as these metals did not react much to create a new substance. Now we have many chemical processes available to extract metals which is why many reactive metals were discovered later on rather than in the far past.

Platinum

DiscoveryAncient Egyptians and Pre-Columbian Indian civilizations already valued Platiunm as a very important element. The "modern" discovery of platinum is attributed to Spanish conquerors in the 17th century. Actually the name platinum was given by the Spanish word, platina, meaning little silver. Spaniards had discovered alluvial deposits of the rare white metal when they were mining in search for gold in the Choco region in Colombia. Paradoxically, they considered platinum as a nuisance for their mining of gold.

ExtractionSince platinum extraction and production is a quite complex process, there is a wide scope for research and technology advances in this field. New technologies are continuously developed to reduce operating costs and increase efficiency in the platinum extraction process.. The high melting points, corrosion resistance, and catalytic properties of this metal has many industrial applications.

Properties•Ductile•Malleable•Silvery-white•Melting point: 1772 °C•Boiling point: 3827 +/- 100 °C•Chemical symbol: Pt•Atomic number: 78•Atomic weight: 195.09

Uses• Jewelry• Catalyst• Electrical Contacts• Dentistry• Crucibles• Thermocouple

Gold

DiscoveryGold was discovered in the Cullomain Village in the Cullumah valley, by a Nisenan man. On January 24, 1848, James Marshall hired by John Sutter to build a lumber mill and supply materials for Sutter's dream empire "New Helvetia" discovered gold in the tailrace of the new mill.

ExtractionGold mining from alluvium ores was once achieved by techniques associated with placer mining such as simple gold panning and sluicing, resulting in direct recovery of small gold nuggets and flakes. Hydraulic mining was used widely in the Californian gold rush, and involved breaking down alluvial deposits with high-pressure jets of water. There is also dredging, cradle, hard rock mining, and byproduct gold mining.

Properties• Chemical Symbol: Au• Mineral: usually found as a native

metal• Relative density: 19.3• Hardness: 2.5-3 on Mohs scale• Malleability: High• Ductility: High• Melting point: 1060°C• Boiling point: 2660°C• Atomic Mass: 196.97

Uses•Jewelry•Electronics•Industry•Medicine•Computers•Dentistry•Awards, Statues•Glassmaking

Silver

DiscoveryEven though the discoverer of silver is unknown, there are records that indicate slag dumps were found in Asia Minor and on the islands in the Aegean Sea. These findings lead to the belief that as early as 4000 B.C. man was able to separate silver from lead.

ExtractionOres rich in silver disappeared long ago due to mining. Today, silver usually comes from ores that contain very small amounts of the metal.. After the primary metal has been removed, the waste often contains small amounts of silver. These wastes are treated with chemicals that react with the silver. The silver can then be extracted by electrolysis. Electrolysis is a process by which a compound is broken down by passing an electric current through it.

Properties• Extremely ductile and malleable• Symbol: Ag• Atomic Number: 47• Atomic Mass: 107.868• FAMILY Group 11 (IB), Transition

metal

Uses•Industrial Uses• Silverware•Ornaments•Photography•Coins•Dentistry•Medical Uses

Copper

DiscoveryNo one knows exactly when copper was first discovered, but earliest estimates place this event around 9000 B.C. in the Middle East. Present-day Israel, Egypt and Jordan were some of the earliest locations of copper smelting sites, dating back to about 4500 B.C. Located in southern Jordan, 30 miles south of the Dead Sea, the 70-room, 5000-year old Kirbat Hamra Ifdan foundry housed such copper artifacts as hammers and axes.

ExtractionThe method used to extract copper from its ores depends on the nature of the ore. Sulphide ores such as chalcopyrite are converted to copper by a different method from silicate, carbonate or sulphate ores.

Properties• Symbol: Cu• Atomic Number: 29• Good electrical conductor• Good thermal conductor• Corrosion Resistant• Antibacterial• Ductile• Malleable• Non Magnetic• Easy to Alloy• Recyclable• Catalytic

Uses• Plumbing• Cookware• Coins• Heat Sinks• Musical Instruments• Wires, Switches• Structures (e.g. Stature of

Liberty)• Lightning Rods

Lead

DiscoveryLead has been around for thousands of years. It is impossible to say when humans first discovered the element. It does not occur as an element in the earth very often. But one of its ores, lead sulfide (PbS), is fairly common. It is not difficult to obtain pure lead metal from lead sulfide. It is said to be discovered during prehistoric times.

ExtractionLead is obtained from its ores by a method used with many metals. First, the ore is roasted (heated in air). Roasting, also called smelting, converts the ore to a compound of lead and oxygen, lead oxide (PbO 2 ). Lead oxide is then heated with charcoal (pure carbon). The carbon takes oxygen away from the lead oxide. It leaves pure lead behind: Lead obtained in this way is not very pure. It can be purified electrolytically. Electrolytic refining involves passing an electric current through a compound. Very pure lead is collected at one side of the container in which the reaction is carried out.

Properties• Symbol: Pb• Atomic number: 82• Atomic weight: 207.2• Extremely soft• Highly malleable and ductile• Poor electrical conductor• Resistant to corrsion• Color: bluish white• Classification: Metallic

Uses• Pencils• Lead-Acid Storage Batteries• Sound Absorber• Radiation Shield• Plumbing, Because It Absorbs

Vibrations

Iron

DiscoveryAncient Egyptians had learned how to use iron before the First Dynasty, which began in about 3400 B.C. The Egyptians probably found the iron in meteorites. Meteorites are chunks of rock and metal that fall from the sky. Some meteorites are very rich in iron. The Egyptians made tools and jewelry out of iron.

ExtractionThe most common way of extracting iron is through a blast furnace. Iron production involves iron ores, principally hematite (nominally Fe2O3) and magnetite (Fe3O4) in a carbothermic reaction (reduction with carbon) in a blast furnace at temperatures of about 2000 °C. In a blast furnace, iron ore, carbon in the form of coke, and a flux such as limestone (which is used to remove silicon dioxide impurities in the ore which would otherwise clog the furnace with solid material) are fed into the top of the furnace, while a massive blast of heated air, about 4 tons per ton of iron is forced into the furnace at the bottom.

PropertiesChemical Symbol:FeMineral: iron oxides: eg hematite and magnetiteRelative density: 7.87Malleability: HighDuctility: HighMelting point: 1535°CAtomic Mass: 55.85

Uses• Ovens• Nails• Machinery• Cutlery• Household Appliances• Building Structure

Diamond

DiscoveryDiamonds began appearing in European jewelry in the thirteenth century, and by the eighteenth century they were abundant in use all over Europe but still rare and exclusive (due to price). However, they were first found by the Indians around 6000 years ago.

ExtractionThere is Artisanal Mining, Hard Rock Mining, Marine Mining, Open Pit Mining and Placer Mining. Artisanal diamond mining (aka "small-scale mining") involves nothing more that digging and sifting through mud or gravel river-bank alluvial deposits with bare hands, shovels, or large conical sieves. Open-pit diamond mining, also known as "open-cast mining" is a method of extracting rock and minerals from the earth by removal from a machine-dug open pit or burrow.

Properties• The Mohs hardness scale, on

which diamond is a ‘10’. • The least compressible and stiffest

substance.• An exceptional thermal conductor -

4 times better than copper.• Can also be an insulator

Uses• Jewelry• Cutting and Grinding Tools• Heat Sinks• Engraving Tools• Windows that are used to cover

openings of lasers, x-rays and vacuum chambers

• Speaker domes that enhance the performance of high quality speakers

Aluminum

DiscoveryAluminium was first isolated by Hans Christian Oersted in 1825 who reacted aluminum chloride (AlCl3) with potassium amalgam, an alloy of potassium and mercury. Heating the resulting aluminum amalgam under reduced pressure caused the mercury to boil away leaving aluminum metal. The metal was born for uses, which at that time no one could have thought of.

ExtractionThe extraction is done by electrolysis. But first the aluminum oxide must be made molten so that electricity can pass through it. Aluminum oxide has a very high melting point (over 2,000°C), so it would be expensive to melt it. Instead, it is dissolved in molten cryolite, an aluminum compound with a lower melting point than aluminum oxide. The use of cryolite reduces some of the energy costs involved in extracting aluminum.

Properties• Ductile• Low melting point and density• Light Weight• Highly Corrosion Resistant• Excellent Heat and Electricity

Conductor

Uses• Aluminum Foil• Coins• Car, Airplane, Truck, Train, Boat

and Bicycle Parts• Electrical Wiring• Electronics• Cans

Reactivity Series

Simpler Version Of Reactivity Series

Reactivity SeriesMetal Date Discovered Does it Follow

the Reactivity Series?

Aluminum 1825 No, because it should have been discovered earlier and at around the bottom of the series.

Diamond (Carbon) 4000 B.C. No, because it should have been discovered earlier and at the bottom of the series.

Iron 3400 B.C. No, because it should have been discovered earlier and at the bottom of the series.

Lead Prehistoric Times Probably, because it is discovered early and is less reactive.

Copper 4500 B.C. No, because it should have been around the bottom of the series and discovered earlier.

Silver 4000 B.C. No, because it should have been discovered earlier and at around the bottom of the series.

Gold 1848 Yes, because it is discovered early.

Platinum Around 1800 Yes, because it is discovered first.

Discovery

I have found out that my ‘hypothesis’ was partially correct. The reactivity of the metal does affect the date it was discovered, in some cases, not all.

Platinum is the least reactive on the reactivity series, however it was not the first to be discovered. Silver, copper, lead, iron and diamond (carbon) were discovered before it. I think that this is because, according to my information on platinum, it is a very difficult metal to extract, whereas the metals discovered before it are easy to extract, thus causing them to be discovered first. Also, since the process for extracting platinum requires lots of research and technology, it probably took the people in the olden days lots for time and effort to extract it, which is why it probably was not discovered first. It is an expensive procedure to extract platinum, whilst the metals discovered before it are cheaper.