The second most abundant element in the universe, helium is rare on Earth. In liquid form it is used as a coolant in super conducting magnets in MRI scanners – so should this rare element be used in something as frivolous as party balloons? And what happens to the helium when that balloon inevitably escapes the clutch of a small child?

(Picture: US National Helium Reserve; Credit: Jonny Dymond/BBC)

Light, strong and flexible, aluminium is used in drinks cans, window frames, aircraft and packaging. Ubiqitous today, why was it valued more highly than gold 150 years ago? Is it better to recycle this metal, or spend vast amounts of energy creating more of it from scratch? And why is Jaguar Landrover teaching robots to rivet?

Mercury is beautiful, yet deadly poisonous. Known as quicksilver, the Minamata international treaty aims to phase its use out completely. But how will the ban on element 80 affect artisanal gold miners? Or coal-fired power stations? And why does so much of this liquid metal end up in tuna and swordfish?

(Picture: Ghanaian artisanal miner holds mercury in his hand; Credit: Matt Davies/BBC)

This metal played a part in the worst car crash in history, the 1955 Le Mans disaster, helping to make the resulting inferno explosively dangerous. Yet despite its fiery reputation, and its proneness to corrosion, magnesium has regained its historic role in making planes and cars lighter and more efficient. Presenter Laurence Knight visits Magnesium Elektron, the company behind the alloy used in the ill-fated Le Mans car, to find out how a new breed of alloys has exorcised the demon's in this metal's past. We also hear from researcher Kristin Persson about an entirely new role magnesium could play in the car industry - as an even lighter and more compact replacement for lithium-ion batteries in electric vehicles.

(Picture: Magnesium alloy flame test; Credit: Magnesium Elektron)

Rare and toxic, beryllium can do serious damage to your lungs. Presenter Laurence Knight explores whether and how we can make use of this metal safely. Prof Andrea Sella of University College London explains why beryllium's surprising scarcity is the very reason it can be so harmful to the body. Gianna Palmer reports from the Hanford nuclear site in Washington State on this chemical element's intimate and poisonous history in the US nuclear weapons programme. And we hear from IBC Advanced Alloys, a company that claims to have a novel, cheap - and safe - way of producing aeroplane parts out of beryllium-aluminium.

Image: A man holding a shockproof X-ray tube - Beryllium is used in the construction of these. Credit: Douglas Miller/Topical Press Agency/Getty Images

Potash plumps up fruit, vegetables and grains, and the potassium it contains is an essential nutrient. Yet India is completely dependent on imports of this critical fertiliser to feed its population.

Presenter Justin Rowlatt visits a farm on the Ganges plains to see how this mineral is used, and speaks to the head of the national importer Indian Potash Ltd about their efforts to promote its use by farmers.

We also hear from Paul Burnside, analyst at CRU Group, how a bust-up in Belarus has helped turn potash into a global buyers' market.

Meanwhile Prof Andrea Sella of University College London recreates everyone's favourite school chemistry experiment, with some unexpected consequences...
(Picture: Indian labourer carries bananas in Chennai; Credit: Arun Sankar/AFP/Getty Images)

Uranium is the fuel for nuclear power stations, which generate carbon-free electricity, but also radioactive waste that lasts a millennium. In the latest in our series looking at the world economy from the perspective of the elements of the periodic table, Justin Rowlatt travels to Sizewell in Suffolk, in a taxi driven by a former uranium prospector.
He is given a tour of the operational power station, Sizewell B, which generates 3% of the UK's electricity, by EDF's head of safety Colin Tucker, before popping next-door to the original power station, Sizewell A, where he speaks to site director Tim Watkins about the drawn-out process of decommissioning and cleaning up the now-defunct reactors.
But while Sizewell remains reassuringly quiet, big explosions come at the end of the programme. We pit environmentalist and pro-nuclear convert Mark Lynas against German Green politician Hans-Josef Fell, the joint architect of Germany's big move towards wind and solar energy, at the expense of nuclear. Is nuclear a green option? It really depends whom you ask.
(Photo: Perdiodic table)

Neither rare nor earths, these 17 elements are nonetheless difficult and unpleasant to mine and refine. Chemically near-identical, these metals have unique magnetic and optical properties, making them essential in modern technology from fibre optics to wind turbines. So should we worry about China's stranglehold over their supply?
(Picture: 20 euro note glows under an ultraviolet light; Credit: Frans Dekkers/Thinkstock)

Carbon is a great energy store – in plants and animals, but also as hydrocarbons – coal, oil and natural gas. From the Industrial Revolution onwards, burning these fossil fuels has released vast quantities of carbon dioxide into the air, affecting our climate and oceans. So can we ever get by without carbon-based energy?

Cobalt, the metal in magnets and phone batteries, is synonymous with the colour blue. But what exactly are magnets, how do they work and where are they used? And is some of the cobalt being mined by children? Presenter Laurence Knight hears from chemistry professor Andrea Sella of University College London why a permanent magnet is like a flock of birds, and he travels to Arnold Magnetics near Sheffield where manager Martin Satyr explains how magnets are used in everything from recovering the heat energy from sportscar engines to recycling your trash. Also in the programme, Mark Dummett of Amnesty International, back from Katanga in southern Congo - source of half the world's cobalt - tells of his concerns about the conditions in which artisanal miners work, including children. And David Weight of the Cobalt Development Institute explains what the industry is doing to ensure it knows where its cobalt is coming from. (Photo: Andrea Sella picking up lumps of cobalt with a magnet; Credit: Laurence Knight)

Lithium is the electro-chemical element - big in batteries and bipolar disorder. Over two decades it has shot from obscurity to become almost synonymous with the way we power our gadgets. Presenter Justin Rowlatt hears from chemistry powerhouse professor Andrea Sella of University College London about what makes lithium so light and energetic. We hear from Gideon Long in Chile, who visits the world's richest source of lithium in the Atacama Desert, and about how neighbouring Bolivia believes it will dominate supply if demand for this alkali metal continues to see double-digit growth. Justin speaks to professor Nigel Brandon of Imperial College, an expert on cutting-edge battery research, about whether lithium can ever realistically hope to challenge a can of petrol as the best way to power a car. And, we hear from clinical psychologist Kay Redfield Jamison of Johns Hopkins University about the literally life-saving role lithium has played for sufferers of bipolar disorder - including herself. (Picture: Salar de Atacama; Credit: Gideon Long)

Could we finally be about to crack this source of potentially unlimited clean energy - thanks in part to a plethora of private sector tech startups?
Laurence Knight travels to one such company, Tokamak Energy in the UK, to hear from plasma physicist Melanie Windridge. Meanwhile the BBC's David Willis reports on the string of secretive new fusion initiatives along the Pacific Coast, and the Silicon Valley money backing them.
Plus, could fusion energy open the way to the economic abundance and space travel portrayed in Star Trek? Laurence speaks to Trekonomics author Manu Saadia.
(Picture: Plasma inside a Tokamak fusion reactor; Credit: Tokamak Energy)

Lead is the sweetest of poisons, blamed for everything from mad Roman emperors to modern-day crime waves. Yet a lead-acid battery is still what gets your car going in the morning. So have we finally learnt how to handle this heavyweight element? Justin Rowlatt travels to arts shop Cornelissen in London's Bloomsbury to find out why they have stopped stocking lead paints, and hears from professor Andrea Sella of University College London about the unique properties that have made this metal so handy in everything from radiation protection to glassware.
Yet lead in petrol is also accused of having inflicted brain damage on an entire generation of children in the 1970s, as the economist Jessica Wolpaw-Reyes of Amherst College explains. And, producer Laurence Knight travels to one of the UK's only two lead smelters - HJ Enthoven's at Darley Dale in Derbyshire, the historical heartland of the UK lead industry - to see what becomes of the lead in your car battery. And, we speak to the director of the International Lead Association, Andy Bush.

Tungsten is one of the hardest, heaviest and highest melting metals, used in everything from bulbs to bullets, x-rays to drill bits. Justin Rowlatt hears from the perennial Professor Andrea Sella of University College London about the properties of what is one of the densest of elements.

We get a tour of the SGS Carbide tool factory with managing director Alan Pearce, and we consider the market value of this very useful element with Mark Seddon, head of consultancy firm Tungsten Market Research.
Should we worry that China dominates demand? And why is it taking so long to open up new sources? We visit the Hemerdon mining project in the pretty English county of Devon, and hear from Russell Clark, head of the mining firm Wolf Minerals that is reopening it.
And, there is a very special reason why your government should care about its tungsten supplies, as military technology analyst Robert Kelley explains.
(Picture: Soldier lays armour-piercing sabot round on the ground during Operation Desert Shield; Credit: US Department of Defense)

Some 78% of the Earth's atmosphere is nitrogen. Yet this seemingly inert gas is the key component of bombs and explosives. It has brought life and death on an epic scale since mankind first unlocked its potential a century ago. And it has brought tragedy to the lives of the scientists who mastered its potential.

(Picture: Early Bosch ammonia reactor in Ludwigshafen; Credit: BASF)

These powerful chemicals are essential to obtain the minerals that build our world, the fertilisers that feed the planet, and the fuels that propel our vehicles - as presenter Laurence Knight discovers on a trip to the Ineos Grangemouth oil refinery in Scotland. But while most traditional acids are based on the power of hydrogen ions, Prof Andrea Sella of University College London explains that many modern industrial "acids" do not, and come in startlingly unexpected forms such as powders. Many of the most corrosive acids are very tricky to contain, resulting in the occasional nasty accident, as chemical engineer Keith Plumb explains. Also, Justin Rowlatt has a report on acid attacks in southern Asia in which he speaks to campaigner Selina Ahmed of the Acid Survivors Foundation on how Bangladesh has tackled the problem. (Picture: A team working with toxic acids and chemicals secures chemical cargo train tanks crashed near Sofia, Bulgaria; Credit: Cylonphoto/Thinkstock)

Titanium is the magic metal that made possible the mass production of plastics and paints, as well as buildings that clean both themselves and the air around them.

Presenter Laurence Knight heads to the Ineos oil refinery in Grangemouth, Scotland, to see how just a smidge of a titanium-based catalyst transforms a type of natural gas into the stuff of food packaging, bottles and car bumpers.

He hears from Prof Andrea Sella why most of us spend our lives surrounded by titanium without even realising it.

And Brian Pickett of pigments manufacturer Cristal explains why his company has been painting various bits of London to further the fight against city smog.

(Picture: Window cleaner; Credit: Peter Parks/Getty Images)

The atomic clock runs on caesium, and has redefined the very meaning of time. But it has also introduced a bug into timekeeping that affects everything from computerised financial markets to electricity grids, and satellite navigation to the Greenwich Meridian.
Justin Rowlatt travels to the birthplace of modern time, the National Physical Laboratory in Teddington, England, to speak to Krzysztof Szymaniec, the keeper of the 'Caesium Fountain', and Leon Lobo, the man charged with disseminating time to the UK. He also hears from Felicitas Arias, director of time at the Bureau International des Poids et Mesures in Paris, about plans to abolish the 'leap second'.
And, the Astronomer Royal, Martin Rees, explains why even the atomic clock can never hope to provide an absolute measure of time.

Itself a ferocious yellow gas, fluorine is also the key building block for a string of other gases that pose a threat to mankind - from the ozone-depleting CFCs to potent greenhouse gases. We track fluorine from the mine to its incredible array of final uses. And we find out why an exploding Mercedes car has caused a trans-Atlantic chemistry tiff.

Sulphur is in abundant supply thanks to its extraction from sour oil and gas, in order to prevent acid rain pollution. But does the world face a glut of this devilish chemical element, famed for its colour and odour? And if so, what uses can it be put to?
Justin Rowlatt has his hair cut as professor Andrea Sella of University College London, demonstrates sulphur's surprisingly plastic - and acrid - qualities. He travels to the leafy London suburb of Twickenham to find out about Joshua Ward, the charlatan who set up the world's first sulphuric acid factory.
We hear from Richard Hands, editor of Sulphur magazine, about the element's many industrial uses, as well as the gigantic heaps of unwanted sulphur piling up in Canada and Florida. And Mike Lumley, who leads efforts at Shell to make use of the oil giant's sulphur bi-product, explains why the end of acid rain has opened up a surprising new source of demand.
Finally, Justin speaks to Dr Robert Ballard - the man who located the shipwreck of the Titanic - about why he actually considers a sulphur-linked oceanic discovery to be his greatest achievement.
(Picture: Sulphur blocks in Alberta, Canada; Credit: David Dodge/Pembina Institute)

In the final programme in our Elements series, Justin Rowlatt looks at the rarest and oddest members of the periodic table.
Selenium, bismuth, molybdenum, antimony, rhenium, hafnium, zirconium, tellurium, thallium, barium. What are they? And what are they used for?
Minor metals merchant Anthony Lipmann explains how he made a fortune tracking down a stockpile of one toxic element sufficient to kill millions of people - and sold it to Japanese camera manufacturers.
We set chemistry professor Andrea Sella a musical challenge to round off his elucidation of the periodic table, going out with a pyrotechnic bang.
And cosmologist Martin Rees explains why 85% of the matter in the universe isn't made up of chemical elements at all, but instead of "dark matter", whatever that is.
(Picture: Elements series planning board; Credit: Laurence Knight/BBC)

Why do we value this practically useless metal so highly? And does it bring out the worst in human nature?
In a second look at this most coveted of metals, Justin Rowlatt hears both sides of the age-old argument. Swiss investor and gold enthusiast Marc Faber explains why he keeps gold bars tucked away at his home in rural Thailand. Meanwhile financial advisor and Big Picture blogger Barry Ritholtz teases goldbugs for succumbing to what he considers their very human irrational tendencies.
Plus, we hear from Bandana Tewari of Vogue magazine about why her home country of India will always be besotted by the bling of gold.
And here's a bonus for what is the penultimate programme in the Elements series. This podcast contains 10 gold-themed songs. If you think you can name some of them, then tweet your guesses to Justin at @BBCJustinR. Get them all right, and Justin might even give you a prize.
(Picture: Indian model sports gold jewellery for Diwali; Credit: Noel Seelam/AFP/Getty Images)

This radioactive metal holds the promise of thousands of years of energy for the world. But is it really any cleaner or safer than traditional uranium-based nuclear power?
Chemistry Professor Andrea Sella of University College London takes the helm, as he speaks to no less than three nuclear physicists in his quest to discover whether thorium will deliver that godlike bolt of electricity, or just remain a nebulous dream.
Prof Bob Cywinski of the University of Sheffield is a fan, whereas Dr Arjun Makhijani of the Institute for Energy and Environmental Research is decidedly not.
Meanwhile India presses ahead with its now 60-year-old thorium energy programme, as former nuclear chief Anil Kakodkar explains.
(Picture: Human hand holding lightning; Credit: Sergey Nivens/Thinkstock)

Six extremely rare metals that clean your car exhaust and turbocharge industrial chemistry, but which are also the focus of a violent power struggle in South Africa.
Presenter Laurence Knight heads to Johnson Matthey, a company that pioneered the car catalytic converter in the 1970s, to find out how they work and to watch the kind of emissions test that Volkswagen cheated.
Andrea Sella of University College London makes a piece of one of these precious metals pop, and explains why platinum crucibles are the bees knees of nineteenth century chemistry.
And the BBC's Vumani Mkhize reports from brutal fight between two unions for supremacy over what is the world's biggest source of platinum group metals.
(Picture: Car exhaust; Credit: ruigsantos/Thinkstock)

The macabre poison we know from crime novels and history books has some surprising modern uses.
Justin Rowlatt travels the Subcontinent - first to India's Forest Research Institute in the Himalayas where Sadhna Tripathi explains why the chemical element ends up in telegraph polls.
We then head to Bangladesh, scene of the "largest mass poisoning in history". Justin speaks to Dr Quazi Quamruzzaman who helped first uncover it, and to Richard Pearshouse of Human Rights Watch, who says the problem still hasn't gone away.
Sanjay Wijesekera of Unicef explains how the road to this particular hell was paved by good intentions, and how his aid agency is helping to guide Bangladesh back out again.
(Picture: Bangladeshi woman's foot showing lesions caused by arsenic poisoning; Credit: Majority World/UIG via Getty Images)

The shiniest and showiest of metals is still mainly used in silverware. But it also has some surprisingly modern applications.
Justin Rowlatt heads deep under the city streets to the sparkling London Silver Vaults to talk tableware and frivolities - the more traditional uses of silver.
We also hear from Dr Alan Lansdown of Imperial College, a champion of silver in medicine (except when it turns you blue), and from Prof Alan Dalton about the future role of silver in flexible touchscreens.
(Picture: Silverware on display at the London Silver Vaults; Credit: Langfords)

Why does iodine deficiency still blight children in developing countries like India?
Justin Rowlatt travels to Dehradun in the Himalayas with world expert Chandrakant Pandav to diagnose schoolchildren still suffering from the throat swelling called goitre, and from the permanent mental retardation known as cretinism.
Justin challenges Indian government officials to explain why, 50 years after India first introduced its salt iodisation programme, this easily solvable problem still persists. (Picture: Woman with large goitre;
Credit: Dr P Marazzi/Science Photo Library)

Could we finally be about to crack this source of potentially unlimited clean energy - thanks in part to a plethora of private sector tech startups?
Laurence Knight travels to one such company, Tokamak Energy in the UK, to hear from plasma physicist Melanie Windridge. Meanwhile the BBC's David Willis reports on the string of secretive new fusion initiatives along the Pacific Coast, and the Silicon Valley money backing them.
Plus, could fusion energy open the way to the economic abundance and space travel portrayed in Star Trek? Laurence speaks to Trekonomics author Manu Saadia.
(Picture: Plasma inside a Tokamak fusion reactor; Credit: Tokamak Energy)

This toxic metal is slowly being phased out of our lives. But as presenter Justin Rowlatt discovers, while nickel-cadmium batteries may have disappeared from our gadgets, they still help to keep planes up in the air.
Chemistry professor Andrea Sella tells the story of this colourful yet poisonous element, while metals consultant Dominic Boyle says even if we stop using it all together, the stuff is still piling up.
Justin visits the offices of SES Batteries in the Indian military town of Ambala to find out why the country's army still uses nickel-cadmium batteries. And Jennifer Holdaway of the Social Science Research Council explains how cadmium found its way into China's rice supplies.
(Picture: Stack of AA nickel-cadmium batteries; Credit: Sergei Chumakov/Thinkstock)

Potash plumps up fruit, vegetables and grains, and the potassium it contains is an essential nutrient. Yet India is completely dependent on imports of this critical fertiliser to feed its population.

Presenter Justin Rowlatt visits a farm on the Ganges plains to see how this mineral is used, and speaks to the head of the national importer Indian Potash Ltd about their efforts to promote its use by farmers.

We also hear from Paul Burnside, analyst at CRU Group, how a bust-up in Belarus has helped turn potash into a global buyers' market.

Meanwhile Prof Andrea Sella of University College London recreates everyone's favourite school chemistry experiment, with some unexpected consequences...
(Picture: Indian labourer carries bananas in Chennai; Credit: Arun Sankar/AFP/Getty Images)

Is the dream of a hydrogen-fuelled zero-carbon economy achievable? Presenters Justin Rowlatt and Laurence Knight ask where the hydrogen will come from and how we will store it.

Professor Andrea Sella of University College London blows up a hydrogen balloon, while Professor James Durrant of Imperial College explains what an artificial leaf is.

In India, Alok Sharma of the Indian Oil Company gives a tour of their hydrogen refuelling station and fuel cell research centre. And Ned Stetson of the US Department of Energy explains why the vexed problem of containing all this hydrogen is forcing them to resort to "complex anions" and other obscure chemistry.
(Picture: An Iwatani serviceman refuels a Toyota Mirai car with hydrogen in Tokyo; Credit: Yoshikazu Tsuno/AFP/Getty Images)

The metal that brings shelter and good health to India's poorest. Presenter Laurence Knight travels to a bustling Delhi where Rahul Sharma of the International Zinc Association explains how this self-sacrificing chemical element fights off the ravages of the city smog, while Dr HP Sachdev runs us through its medical benefits.
In Rajasthan Sunil Duggal, chief executive of Hindustan Zinc Ltd, explains how mining operations such as at the gigantic Rampura Agucha will help feed India's coming construction boom. Meanwhile, back in London Justin Rowlatt blows his trumpet.
(Picture: Slum rooftops in Mumbai; Credit: Daniel Berehulak/Getty Images)

As climate change threatens to play havoc with the rain, could we instead draw our water directly from the ocean?
In his second gulp of H2O, presenter Justin Rowlatt hears from climatologist Raymond Pierrehumbert about how global warming is causing drastic but often unpredictable disruption to our natural supplies of freshwater.
Yet as Israel enters its third year of dought, few of the country's citizens are aware of any water shortages. The BBC's Shira Gemer reports on the technological breakthroughs that have made this possible - from the gigantic Sorek desalination plant, to the drip irrigation pioneered by Netafim in the Negev desert.
We also hear from desalination expert Raphael Semiat of Technion University how much the rest of the world can emulate Israel's success.
(Picture: Icebergs float in the Jacobshavn Bay in Greenland; Credit: Uriel Sinai/Getty Images)

Northwest India is fast running out of groundwater. As much of the world faces growing water scarcity, will mass migration and water conflicts become inevitable? Do we take water for granted at our peril? Presenter Justin Rowlatt hears from chemistry professor Andrea Sella of University College London why water is essential for life, and why it is far weirder than we realise. Laurence Knight reports from a parched Rajasthan on what can be done to stop farmers there from pumping the ground dry. And water expert Claudia Ringler of the International Food Policy Research Institute discusses how bad things could get.
(Picture: Man walks across bed of a dried-out lake in Ahmedabad, India; Credit: Sam Panthaky/Getty Images)

Neon, argon, krypton and xenon: Laurence Knight investigates their uses, from the blinding light of the arc welder's torch to the dying trade of the neon sign-making.

Professor Andrea Sella explains how an alumnus of his home University College London - Scottish chemist Sir William Ramsay - uncovered an entire column of the periodic table containing all of these unreactive gases.

Neon sign-maker Graham Cox shows how to bring colour and light to the dingiest of corners, while neon artist Marcus Bracey welcomes us to his gallery, God's Own Junkyard, where he insists the future for these gaseous elements remains bright.
(Picture: “Find Love Upstairs” artwork by Chris Bracey at the God’s Own Junkyard neon art gallery)

Nanotech, virtual reality, Moore's Law - we look at germanium, the substance that could oust the silicon from Silicon Valley, and one day help computers supercede your brain.

IBM's head of innovation, Bernie Meyerson, showcases the company's new prototype 7nm germanium-silicon chip - containing the tiniest transistors yet at just 35 atoms across. Presenter Laurence Knight heads to Oxford to scrutinise the equally tiny images made by startup Bodle Technologies out of wonder material GST. And he hears from another IBM material scientist - Abu Sebastian, based in Zurich - about how GST could help us build thinking computers that might one day outsmart us all.

(Picture: IBM's prototype 7nm silicon-germanium chip; Credit: Darryl Bautista/Feature Photo Service for IBM)

Radium, polonium and radon may be names to make your hair stand on end, but are they actually useful for anything? And is our fear of them overbaked? Laurence Knight gets the chemistry rundown from Prof Andrea Sella of University College London at a hospital that used to treat cancer with radiation. Al Conklin of the Washington State Department of Health explains how we are still dealing with the world's early Twentieth Century craze for all things radioactive. Edwin Lane reports from Finland on how the country's geology and climate conspired to fill their houses with a radioactive gas. Plus, we hear from Prof Norman Dombey, a key expert witness in the public enquiry into the murder of Alexander Litvinenko.
(Picture: Glow-in-the-dark radium clock dial; Credit: Ted Kinsman/Science Photo Library)

Is coltan - the notorious conflict mineral from which these two metals are derived - still being smuggled from DR Congo into Rwanda, to evade taxes and sourcing controls? Laurence Knight investigates the hi-tech roles to which these two chemical elements are put in gadgets and telecommunications. He also discusses the bloody history behind the mining of their ore in the heart of Africa with Sophia Pickles of human rights organisation Global Witness. And the BBC challenges the Rwandan authorities and chipmaker Intel about what they are doing to address allegations of current-day smuggling of coltan across the border from Congo to be laundered in Rwanda.
(Picture: A miner cleans freshly dug coltan ore at the Abahizi cooperative mine in Ngara, Rwanda)

Rare and toxic, beryllium can do serious damage to your lungs. Presenter Laurence Knight explores whether and how we can make use of this metal safely. Prof Andrea Sella of University College London explains why beryllium's surprising scarcity is the very reason it can be so harmful to the body. Gianna Palmer reports from the Hanford nuclear site in Washington State on this chemical element's intimate and poisonous history in the US nuclear weapons programme. And we hear from IBC Advanced Alloys, a company that claims to have a novel, cheap - and safe - way of producing aeroplane parts out of beryllium-aluminium.

Image: A man holding a shockproof X-ray tube - Beryllium is used in the construction of these. Credit: Douglas Miller/Topical Press Agency/Getty Images

This metal played a part in the worst car crash in history, the 1955 Le Mans disaster, helping to make the resulting inferno explosively dangerous. Yet despite its fiery reputation, and its proneness to corrosion, magnesium has regained its historic role in making planes and cars lighter and more efficient. Presenter Laurence Knight visits Magnesium Elektron, the company behind the alloy used in the ill-fated Le Mans car, to find out how a new breed of alloys has exorcised the demon's in this metal's past. We also hear from researcher Kristin Persson about an entirely new role magnesium could play in the car industry - as an even lighter and more compact replacement for lithium-ion batteries in electric vehicles.

(Picture: Magnesium alloy flame test; Credit: Magnesium Elektron)