And as late as in the toy manufacturer Mattel was forced to recall millions of toys made in China that had been coloured with lead paint. Meanwhile, a toxic trickle of lead from solder and the electrodes of batteries leaches slowly from landfill sites throughout the world. In the European Union effectively banned lead from most consumer electronics, but it remains in use elsewhere. To alchemists, lead was the lowliest of metals - in a sense, it was where all metals started.
In talk of base metals, which alchemy tried to turn to silver and gold, there was none so base as lead. The alchemists believed that lead slowly matured into other metals in the ground.
But alchemy also offered lead a chance to shake off its grey and graceless image. It does not take much to draw splendid colours out of lead. The ancient technologists blanched the dull metal by placing lead strips in pots with vinegar, and shutting them away in a shed full of animal dung. The vinegar fumes and gas from fermenting dung conspired to corrode lead into lead white. Heat this gently, and it turns yellow: a form of lead oxide known as litharge or, in the Middle Ages, massicot.
Heat it some more, and it goes bright red, as you form a different kind of oxide. Both of these substances were used by artists - red lead was, for a long time, their finest red, used for painting many a bright robe in the Middle Ages. It was the signature colour of Saint Jerome. To the alchemists, those colour changes weren't just a way to make pigments. They signified some more profound alteration taking place in the metal, bringing it close to the colour of gold.
It's no wonder, then, that their experiments often began with lead. They came no closer to making real gold, but they started to explore the processes of chemical transformation. Lead, however, seems habituated to revealing its true and dirty colours. Exposed to air, it may go on taking up oxygen until it turns black.
Red lead has become chocolate brown on paintings throughout the world, from Japan to India to Switzerland. In urban galleries there is another danger, as the sulfurous fumes of pollution react with red lead to from black lead sulphide. There seems to be no getting away from it: lead has a glum and melancholy heart.
Phil Ball plumbing the depths of the scientific story of lead. The next edition of Chemistry in its element promises to be a record breaker. You can learn a lot about someone by meeting their family and the same is true for the element. That's how we come to know so much about astatine. Often trumpeted as the rarest naturally occurring element in the world, it's been estimated that the top kilometre of the earth's crust contains less than 50 mg of astatine making it Guinness world record's rarest element.
And you can hear Mark Peplow telling the tale of the world's rarest chemical in next week's Chemistry in its element. I'm Chris Smith, thank you for listening, see you next time. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists. There's more information and other episodes of Chemistry in its element on our website at chemistryworld.
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Facebook Twitter LinkedIn Youtube. Discovery date. Discovered by. Origin of the name. The name comes from the Anglo-Saxon word for the metal, 'lead'. Melting point. Boiling point. Atomic number. Relative atomic mass. Key isotopes. Electron configuration. CAS number. ChemSpider ID. ChemSpider is a free chemical structure database.
Electronegativity Pauling scale. Common oxidation states. Atomic mass. Half life. For example, children living in older homes can still breathe in or ingest dust or paint chips from peeling lead paint on the walls. Lead can also leach into the drinking water supply through older, corroded lead pipes, faucets and solder. Nearly all homes built before the s have lead solder connecting to copper pipes, according to Plumbing Manufacturers International. Even some major U. When the water chemistry is very carefully controlled, however, it keeps lead from leaching into the drinking water.
Most cases of lead poisoning are due to chronic low-dose exposure. Since symptoms of slow lead poisoning are mainly emotional and mental in nature, lead poisoning may be the last thing people suspect. Children are at the greatest risk. Lead can delay physical and mental development in babies and young children. In adults, slow accumulation of lead can result in kidney and nervous system damage, anemia, stroke or cancer, according to Utah State University. Quan Lu is an associate professor of environmental genetics and pathophysiology at Harvard T.
Chan School of Public Health. He is the senior author of a recent study investigating the harmful effects of lead on neural stem cells and children's neurodevelopment. Pb neurotoxicity is determined by intricate interplays between the metal and target neural cells, and there is overwhelming evidence documenting the detrimental effects of Pb in neurons," he told Live Science. Recent incidences of Pb contamination in drinking water in several U. One of the most notorious cases of lead leaching into drinking water occurred recently in Flint, Michigan.
The ancient Egyptians and Greeks used lead in cosmetics, glass and enamels. Other early civilisations used lead to make coins, as a writing material and for medicinal purposes. During the Middle Ages, lead was commonly used in roofing and piping due to its malleability and durability.
In , builders used tonnes of thin lead panels to cover the roof of Notre Dame Cathedral, and later tonnes went into its spire. Lead was also a key component in the construction of firearms and printing presses. Lead production increased during the Industrial Revolution due to a growing demand for lead paints and plumbing. Some ancient uses of lead continue today — weights, roofing materials, organ pipes and sculptures. Other uses are more modern — radiation shields in medical X-ray rooms and nuclear science labs and in lead-acid batteries.
The buildings use base isolators to protect them during an earthquake. The lead core deforms during an earthquake, absorbing some of the energy, and then reverts to its original shape. It was during the Industrial Revolution that doctors noticed diseases like gout were more commonly found in painters and plumbers than in the rest of the population. In New Zealand, lead was removed from all but clearly labelled special-purpose paints in and banned from petrol in The useful links section at the end of this article has information regarding lead poisoning, treatment and prevention.
Science and society can have differing views on an issue. When it was proposed to add lead to petrol in the s, scientists advised that it would be dangerous to people and the environment.
The desire for cheaper fuel and safer cars prevailed, and lead was added. As scientific evidence on the dangers of lead grew, public intolerance of lead also grew, and leaded petrol was banned. Add to collection.
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