Transcript :
Chemistry in its element: aluminium
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You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry.
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Chris Smith
This week the chemical cause of transatlantic linguistic friction. Is it an um or an ium at the end? It turns out us Brits might have egg on our faces as well as a liberal smattering of what we call aluminium.
Kira J. Weissman
'I feel like I'm trapped in a tin box at 39000 feet'. It's a common refrain of the flying-phobic, but maybe they would find comfort in knowing that the box is actually made of aluminium - more than 66000 kg of it, if they're sitting in a jumbo jet. While lamenting one's presence in an 'aluminium box' doesn't have quite the same ring, there are several good reasons to appreciate this choice of material. Pure aluminium is soft. However, alloying it with elements such as such as copper, magnesium, and zinc, dramatically boosts its strength while leaving it lightweight, obviously an asset when fighting against gravity. The resulting alloys, sometimes more malleable than aluminium itself, can be moulded into a variety of shapes, including the aerodynamic arc of a plane's wings, or its tubular fuselage. And whereas iron rusts away when exposed to the elements, aluminium forms a microscopically thin oxide layer, protecting its surface from further corrosion. With this hefty CV, it's not surprising to find aluminium in many other vehicles, including ships, cars, trucks, trains and bicycles.
Happily for the transportation industry, nature has blessed us with vast quantities of aluminium. The most abundant metal in the earth's crust, it's literally everywhere. Yet aluminium remained undiscovered until 1808, as it's bound up with oxygen and silicon into hundreds of different minerals, never appearing naturally in its metallic form. Sir Humphrey Davy, the Cornish chemist who discovered the metal, called it 'aluminum', after one of its source compounds, alum. Shortly after, however, the International Union of Pure and Applied Chemistry (or IUPAC) stepped in, standardizing the suffix to the more conventional 'ium'. In a further twist to the nomenclature story, the American Chemical Society resurrected the original spelling in 1925, and so ironically it is the Americans and not the British that pronounce the element's name as Davy intended.
In 1825, the honour of isolating aluminium for the first time fell to the Danish Scientist Hans Christian Øersted. He reportedly said of his prize, 'It forms a lump of metal that resembles tin in colour and sheen" - not an overly flattering description, but possibly an explanation for airline passengers' present confusion. The difficulty of ripping aluminium from its oxides - for all early processes yielded only kilogram quantities at best - ensured its temporary status as a precious metal, more valuable even than gold. In fact, an aluminium bar held pride of place alongside the Crown Jewels at the 1855 Paris Exhibition, while Napoleon is said to have reserved aluminium tableware for only his most honoured guests.
It wasn't until 1886 that Charles Martin Hall, an uncommonly dogged, amateur scientist of 22, developed the first economic means for extracting aluminium. Working in a woodshed with his older sister as assistant, he dissolved aluminium oxide in a bath of molten sodium hexafluoroaluminate (more commonly known as 'cryolite'), and then pried the aluminium and oxygen apart using a strong electrical current. Remarkably, another 22 year-old, the Frenchman Paul Louis Toussaint Héroult, discovered exactly the same electrolytic technique at almost exactly the same time, provoking a transatlantic patent race. Their legacy, enshrined as the Hall-Héroult process, remains the primary method for producing aluminium on a commercial scale - currently million of tons every year from aluminium's most plentiful ore, bauxite.
It wasn't only the transportation industry that grasped aluminium's advantages. By the early 1900s, aluminium had already supplanted copper in electrical power lines, its flexibility, light weight and low cost more than compensating for its poorer conductivity. Aluminium alloys are a construction favourite, finding use in cladding, windows, gutters, door frames and roofing, but are just as likely to turn up inside the home: in appliances, pots and pans, utensils, TV aerials, and furniture. As a thin foil, aluminium is a packaging material par excellence, flexible and durable, impermeable to water, and resistant to chemical attack - in short, ideal for protecting a life-saving medication or your favourite candy bar. But perhaps aluminium's most recognizable incarnation is the aluminium beverage can, hundreds of billions of which are produced annually. Each can's naturally glossy surface makes as an attractive backdrop for the product name, and while its thin walls can withstand up to 90 pounds of pressure per square inch (three times that in a typical car tyre), the contents can be easily accessed with a simple pull on the tab. And although aluminium refining gobbles up a large chunk of global electricity, aluminium cans can be recycled economically and repeatedly, each time saving almost 95% of the energy required to smelt the metal in the first place.
There is, however, a darker side to this shiny metal. Despite its abundance in Nature, aluminium is not known to serve any useful purpose for living cells. Yet in its soluble, +3 form, aluminium is toxic to plants. Release of Al3+ from its minerals is accelerated in the acidic soils which comprise almost half of arable land on the planet, making aluminium a major culprit in reducing crop yields. Humans don't require aluminium, and yet it enters our bodies every day - it's in the air we breathe, the water we drink, and the food we eat. While small amounts of aluminium are normally present in foods, we are responsible for the major sources of dietary aluminium: food additives, such as leavening, emulsifying and colouring agents. Swallowing over-the-counter antacids can raise intake levels by several thousand-fold. And many of us apply aluminium-containing deodorants directly to our skin every day. What's worrying about all this is that several studies have implicated aluminium as a risk factor for both breast cancer and Alzheimer's disease. While most experts remain unconvinced by the evidence, aluminium at high concentrations is a proven neurotoxin, primarily effecting bone and brain. So, until more research is done, the jury will remain out. Now, perhaps that IS something to trouble your mind on your next long haul flight.
Chris Smith
Researcher Kira Weissman from Saarland University in Saarbruken, Germany with the story of Aluminium and why I haven't been saying it in the way that Humphrey David intended. Next week, talking of the way the elements sound, what about this one.
Brian Clegg
There aren't many elements with names that are onomatopoeic. Say oxygen or iodine and there is no clue in the sound of the word to the nature of the element, but zinc is different - zinc, zinc, zinc, you can almost hear a set of coins falling into an old fashioned bath. It just has to be a hard metal. In use, zinc is often hidden away, almost secretive. It stops iron rusting, sooths sunburn, keeps dandruff at bay, combines with copper to make a very familiar gold coloured alloy and keeps us alive but we hardly notice it.
Chris Smith
And you can catch up with the clink of zinc with Brian Clegg on next week's Chemistry in its element. I'm Chris Smith, thank you for listening and goodbye.
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Chemistry in its element is brought to you by the Royal Society of Chemistry and produced bythenakedscientists.com. There's more information and other episodes of Chemistry in its element on our website atchemistryworld.org/elements.
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FAQs
What are the properties and uses of aluminium element? ›
Aluminium is a silvery-white, lightweight metal. It is soft and malleable. Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts.
What is the use of aluminum element? ›The metal and its alloys are used extensively for aircraft construction, building materials, consumer durables (refrigerators, air conditioners, cooking utensils), electrical conductors, and chemical and food-processing equipment.
What are two properties of aluminium that are related to this use? ›The property of Aluminium used are low density, high ductility, resistance to corrosion and also good conductivity. It is a good conductor of electricity making it suitable for electrical transmissions.
What is the element of aluminum? ›Aluminum is a chemical element with symbol Al and atomic number 13. Classified as a post-transition metal, Aluminum is a solid at room temperature.
What are 4 major uses of aluminium? ›- Architectural. Because aluminium is both strong and lightweight it is ideal for architectural applications. ...
- Transportation. Aluminium is used for in transportation because of its weight and strength. ...
- Consumer Goods. ...
- Electrical.
- Non-corrosive.
- Easily machined and cast.
- Lightweight yet durable.
- Non-magnetic and non-sparking.
- Good heat and electrical conductor.
- High-rise establishments.
- Consumer electronics.
- Window and door frames.
- Industrial and household appliances.
- Power lines.
- Spacecraft components.
- Land and sea vehicles.
It is commonly used for food and beverages such as milk and soup but also for products such as oil, chemicals, and other liquids. Global production is 180 billion annually and constitutes the largest single use of aluminum globally.
Which property of aluminium is being used here? ›Malleability, a property by which a metal can be beaten into very thin sheets.
Which property of metal is used in aluminium? ›The property by which metals can be hammered into sheets is called malleability. Aluminium, thus being a metal, can be hammered into thin sheets like aluminium foil, which is used in the packaging of food items.
Is aluminium flammable? ›
* Aluminum is on the Hazardous Substance List because it is regulated by OSHA and cited by ACGIH, DOT, NIOSH, DEP, NFPA and EPA. * This chemical is on the Special Health Hazard Substance List because it is FLAMMABLE in powder form.
Can aluminum rust? ›Does Aluminium Corrode? While aluminium doesn't rust, it does corrode. The aluminium oxide coating is highly resistant and renews itself if damaged keeping the metal relatively safe from corrosion. But some factors can cause the coat to become unstable, thus exposing the metal.
Is aluminium a strong metal? ›Many aluminum grades can be considered of very high strength, even comparable to some steels. Nevertheless, comparing samples of the same size of the strongest aluminum alloys and steel alloys, more often than not, steel will be the strongest.
What aluminum is most often used? ›Alloy 3003: The most widely used of all aluminum alloys. A commercially pure aluminum with added manganese to increase its strength (20% stronger than the 1100 grade). It has excellent corrosion resistance, and workability. This grade can be deep drawn or spun, welded or brazed.
Does aluminum react with water? ›Aluminum metal will readily react with water at room temperature to form aluminum hydroxide and hydrogen. That reaction doesn't typically take place because a layer of aluminum oxide naturally coats the raw metal, preventing it from coming directly into contact with water.
Is aluminum magnetic? ›A changing magnetic field will cause an electric current to flow when there is a closed loop of an electrically conducting material. Even though the aluminum can is not magnetic, it is metal and will conduct electricity.
What are the 6 main properties of metals? ›- high melting points.
- good conductors of electricity.
- good conductors of heat.
- high density.
- malleable.
- ductile.
The history of aluminium was shaped by the usage of its compound alum. The first written record of alum was in the 5th century BCE by Greek historian Herodotus. The ancients used it as a dyeing mordant, in medicine, in chemical milling, and as a fire-resistant coating for wood to protect fortresses from enemy arson.
What are five common applications of aluminum? ›The applications include roofing, foil insulation, windows, cladding, doors, shopfronts, balustrading, architectural hardware and guttering. Aluminium is also commonly used as the in the form of treadplate and industrial flooring.
What are the properties of aluminum for kids? ›Characteristics and Properties
In standard conditions aluminum is a fairly soft, strong, and lightweight metal. Its color is silvery-gray. Pure aluminum is a very reactive element and is rarely found on Earth in its free form. Aluminum acts as an excellent conductor of electricity and heat, but is non-magnetic.
What products are made from aluminum? ›
Aluminium is used in tables, chairs, shutters, picture frames, lamps, decorative wall panels, air conditioning units and radiators. Designers use aluminium because it gives them a lot of freedom in choosing the shape for their creations, as well as being easy to process and aesthetically pleasing.
How many types of aluminum do we have? ›Aluminum comes in three basic types: 1100, 3003, and 6061. The grade of the aluminum will determine the end-use application and price point. For example, 1100 is a lower-cost material than 6061 but cannot be used for high-temperature applications like cooking utensils or pot lids.
Why is aluminum important to humans? ›Aluminum compounds have many different uses, for example, as alums in water-treatment and alumina in abrasives and furnace linings. They are also found in consumer products such as antacids, astringents, buffered aspirin, food additives, cosmetics, and antiperspirants.
Why do humans need aluminum? ›No known physiologic need exists for aluminum; however, because of its atomic size and electric charge (0.051 nm and 3+, respectively), it is sometimes a competitive inhibitor of several essential elements with similar characteristics, such as magnesium (0.066 nm, 2+), calcium (0.099 nm, 2+), and iron (0.064 nm, 3+).
Is aluminum important for life? ›Aluminum is neither required by biological systems nor is it known to participate in any essential biological processes. While today all living organisms contain some aluminum, there is no scientific evidence that any organism uses aluminum for any biological purpose.
Is aluminum heavy or light? ›Aluminium has a low density, which means it is lightweight and easy to move. For this reason, it is preferred metal choice when building aeroplanes. While being lightweight, the material is also very strong and easy to shape, making it the perfect choice for manufacturing.
Does aluminum hold heat? ›Which Metals Conduct Heat The Best? As you can see, out of the more common metals, copper and aluminum have the highest thermal conductivity while steel and bronze have the lowest. Heat conductivity is a very important property when deciding which metal to use for a specific application.
Why is aluminum the best metal? ›Aluminum is a very desirable metal because it is more malleable and elastic than steel. Aluminum can go places and create shapes that steel cannot, often forming deeper or more intricate spinnings. Especially for parts with deep and straight walls, aluminum is the material of choice.
Why is aluminium used for cooking? ›Aluminium is a ductile metal and it has a high melting point and good thermal conductivity. Metals like copper and aluminium and alloys like steel are mostly used to make utensils. Due to their ability to conduct heat, copper and aluminium are the most common metals that are used as utensil materials.
Can aluminium be used for cooking? ›Aluminium conducts heat quickly and is quite sturdy which is why it is widely used by people. However, when heated up, aluminium can react with acidic foods like tomatoes and vinegar. This reaction can make the food toxic and might also lead to stomach troubles and nausea.
What is the strength of aluminum? ›
The tensile strength of pure aluminium is around 90 MPa but this can be increased to over 690 MPa for some heat-treatable alloys.
Is aluminium magnetic or steel? ›That's why steel, which contains iron, will be attracted to a magnet. Most other metals, for example aluminium, copper, and gold, are not magnetic.
Does aluminum melt or burn? ›In fact, most metals, except for the noble ones, burn when exposed to conditions that are oxidizing enough, and with a high enough surface-to-volume ratio. But under any reasonable conditions, aluminium sheet and structural beams don't burn.
What color does aluminum burn? ›| Symbol | Name | Color |
|---|---|---|
| Al | Aluminium | Silver-white, in very high temperatures such as an electric arc, light blue |
| As | Arsenic | Blue |
| B | Boron | Bright green |
| Ba | Barium | Pale/Apple Green |
At what temperature does aluminium melt? Aluminium has a higher melting point compared to other metals like copper, iron and brass. In its pure form its melting point is recorded at approximately 660 degrees Celsius or 1220 degrees Fahrenheit.
Does aluminum stick to a magnet? ›Aluminium, on the other hand, is quite different. While it's not far behind in terms of conductivity, it is not attracted to magnets as iron is.
How long does aluminum last? ›Aluminium is the most abundant metallic element on Earth, which is a lightweight and silvery-white metal with a lifespan of over 40 years for building and over 80 years for window frames.
Why does aluminum turn black? ›Like cast-iron cookware, aluminum pans should avoid the machine at all costs. "The combination of alkaline dishwasher detergent, high heat, and minerals in your water can trigger a reaction that darkens the metal," says Jennie Varney, brand manager for Molly Maid.
Can aluminum stop a bullet? ›Aluminum armor can deflect all the same rounds from small-caliber weapons as traditional bulletproof glass. But while traditional bulletproof glass warps, fogs, or spiderwebs when shot, transparent aluminum remains largely clear. It also stops larger bullets with a significantly thinner piece of material.
Is aluminium Flexible? ›Aluminium is among the most flexible design materials available, being both durable and lightweight, it's a maintenance free alternative for a range of applications.
Is aluminium a rare metal? ›
Aluminum is the most abundant metal on Earth, and one of the cheapest to buy. But it used to be more valuable than gold. Aluminum is the third most common element in the Earth's crust, but it also bonds easily with other elements.
What are the main physical properties of aluminium? ›The Physical Properties of Aluminum
Solid, nonmagnetic, non-lustrous, silvery-white with slight bluish tint. Aluminum has a face-centered cubic structure that is stable up to melting point. Aluminum surfaces can be highly reflective.
Properties of aluminium
Lightweight: Almost three times lighter than iron. Durable: Almost as durable as steel. Ductile: Extremely flexible and easily processed using pressure when hot or cold. Corrosion-resistant: Its surface is protected by an extremely thin yet very strong layer of aluminium oxide.
Aluminium is widely used in the packaging industry for the production of coils, cans, foils, and other wrapping materials. It is also a component of many commonly used items such as utensils and watches. In construction industries, aluminium is employed in the manufacture of doors, windows, wires, and roofing.
What are 10 physical properties of aluminium? ›- It is a silvery-white metal.
- It has low density and it is light in weight.
- It is malleable and ductile.
- It is a good conductor of heat and electricity.
- The melting point of aluminium is 660∘C.
- It can be polished to produce a shiny attractive appearance.
The tensile strength of pure aluminium is around 90 MPa but this can be increased to over 690 MPa for some heat-treatable alloys.
What are the uses of aluminium in houses? ›Window frames, panels, domed roofs and other wide-span constructions and ornaments were increasingly made with Aluminium. Today, it is used for roofs, siding, translucent panes, window and doorframes, staircases, air conditioning systems, solar protection, heating systems, furniture and many other things.
What are the advantages and disadvantages of aluminium? ›- Advantages: The most abundant metal in the Earth's crust, Aluminium is relatively soft, durable, lightweight, ductile and malleable metal. ...
- Disadvantages: It's not particularly strong and is expensive compared to steel of the same strength.