1734:
1512: – nicknamed 'the pope' by his colleagues for his infallibility, realised the potential of the newly discovered neutron in the search for elements heavier than uranium. Until now, scientists had been bombarding uranium with alpha particles in the hope they would enter the nucleus. Unfortunately, this was very unlikely because both alpha particles and nuclei are positively charged – the alpha particles could never overcome the electrostatic repulsion of the nucleus.
617:
773:
495:
quantities were the same. Lavoisier realised that something was absorbed from the air when mercury was heated to make mercuric calc, and that same gas was released when the mercuric calc was heated. Lavoisier concluded that this gas was unrelated to phlogiston, but was in fact a brand new element, which he named
686:, Berzelius spent the next ten years obsessively measuring more than two thousand chemical compounds in pursuit of accurate atomic weights for the elements. Eventually Berzelius had remarkably accurate atomic weights for 45 elements; his value for chlorine was accurate to within 0.2% of the value we know today.
509:
1675:
In addition to producing new elements, scientists are also attempting to discern their properties. Copernicium is found to be a volatile metal that would be liquid at room temperature if enough were ever made – exactly what
Mendeleev would predict for an element that sits directly beneath liquid
1284:
The ability of carbon to form four bonds also means it can exist in a huge variety of chemical structures, such as long chains and even rings, making it a rarity amongst the elements. This helped to explain the abundance of carbon in all life forms, from protein and fat, to DNA and cellulose, and why
1047:
Mendeleev's periodic table had brought order to all the elements, allowing him to make predictions that future scientists tested and found to be true. By the time he died he was world-renowned in chemistry. His periodic table was set in stone in St
Petersburg and an element was eventually named after
763:
Whereas
Berzelius' results had failed to convince anyone, Cannizzaro's method set an agreed standard for measuring atomic weights accurately. Chemists soon found that even with accurate atomic weights, the elements still seemed unordered, but then, a solitary English chemist made a curious discovery.
540:
In revenge for his sympathies with the revolutionaries in France, Priestley's home in
England was targeted by arsonists in 1791, luckily he escaped thanks to a tip-off, but decided to flee to America. Lavoisier's contributions to science were cut short in 1794 by the revolutionaries, who arrested him
1584:
Meitner's work was published in 1939, but as well generating interest amongst the scientific community, Meitner's revelations were also coming to the attention of governments on the verge of war. Fuelled by fears Nazi
Germany was investigating nuclear weapons of its own, scientists were assembled in
1187:
in which he describes a compound called silver cyanate, made in equal parts of silver, carbon, nitrogen and oxygen, which he described as harmless and stable. Von Liebig immediately wrote back a furious letter condemning Wöhler as a hopeless analyst: those elements combined in equal proportions were
759:
was still convinced that atomic weights held the key to the order of the elements and had found a new way of measuring them. Cannizzaro knew that equal volumes of gases contain equal numbers of particles, therefore instead of working with solids and liquids and all the unreliability that entails, he
464:
In 1774 Priestley performed a hugely important experiment: he heated mercuric calc and collected the gas given off. He discovered that this gas was able to relight the embers of a previously lit wooden splint. He concluded that the splint was introducing phlogiston to the gas, only after which could
250:
was told he would have to have his leg amputated in a life-saving operation. Instead of accepting the received wisdom, he called upon
Paracelsus who cured him in the unconventional way of using his alchemical knowledge. This established him as a radical thinker, giving weight to his ideas, principal
1112:
Because this is the number of protons, the atomic number must be a whole number – there cannot be any fractional values. Moseley realised it was the atomic number, not the atomic weight that determines the order of the elements. What's more, because the atomic number increases in whole numbers
1077:
introduced the idea that electrons occupied "fixed shells" around the nucleus, which was further developed when it was suggested that each such shell could only accommodate a fixed number of electrons: 2 in the first shell; 8 in the second shell; 18 in the third shell, and so on, each shell holding
607:
At the beginning of the 19th century only 55 of the 92 naturally occurring elements had been discovered. Scientists had no idea how many more they might find, or indeed if there were an infinite number of elements. They also sought to answer a fundamental question, namely: is there a pattern to the
490:
Lavoisier weighted a sample of tin, then reweighed after he had heated it and found it had increased in mass. This was an unexpected result given that the tin was thought to have released phlogiston during the burning process. Lavoisier was struck with a ground-breaking thought – maybe the tin
564:
had recently been invented (rows of metal plates and cardboard soaked in saltwater). Although scientists were aware that the production of a continuous electric current was due to some property of the metals, Davy believed that a chemical reaction was taking place. If that was true, then maybe the
494:
To investigate this further, Lavoisier reran
Priestley's experiment in reverse – he heated some mercury in a sealed container until it turned into mercuric calc and measured the amount of air absorbed. He then heated the mercuric calc and measured the amount of air released and discovered the
486:
Priestley told
Lavoisier all the details of his experiments upon the production of dephlogisticated air. Unlike Priestley, Lavoisier had one of the best equipped laboratories in Europe and now turned his attention to the highly accurate measurement of the masses of substances before and after they
277:
from the human body, and struck upon the idea of using urine, thinking that urine might contain some part of the 'life force' vital to sustaining human life. To get rid of the unimportant parts, primarily water, Brand boiled the urine for several days until he was left with a thick paste. Finally,
1568:
However, in doing the calculations for such an event, Meitner was unable to make the equations balance. She calculated that the products of the fission reaction were lighter than the initial uranium, by about one fifth of a proton. Somehow, a small amount of mass had disappeared. Then slowly, the
1459:
had already revealed the structure of an atom to consist mostly of empty space with a dense nucleus of protons at the centre, and Henry Mosley had shown that it is the number of protons that gives an atom its identity as a particular element. An atom of the element carbon has 6 protons, whilst an
1153:
was trying to produce a synthetic red paint. He started by heating potash (potassium carbonate), with no idea that his potash had been contaminated with blood. When heated, the proteins in blood are altered, allowing them to combine with the iron in the blood, whilst the carbonate reacts with the
1057:
The periodic table does not however tell us why some elements are highly reactive, others completely inert, why some are volatile, whilst others less so. It wasn't until the beginning of the 20th century that an entirely different branch of science began to unravel the answers to these questions.
811:
By 1869 Mendeleev had been trying to find an order for the elements for a decade. One day he struck upon the idea of making up a pack of cards with the elements' names on and began playing a game he called 'chemical solitaire'. He began laying out the cards, over and over, just to see if he could
637:
Dalton suggested that everything in the universe was made of atoms, and that there are as many kinds of atoms as there are elements, each one with its own signature weight. Based on these ideas, working completely alone, Dalton attempted to impose some order on the elements by drawing up a list,
568:
Davy heated the potash until it was liquid, then introduced two electrodes and passed a current through the molten potash. A lilac flame was observed, the result of successfully breaking down potash into its constituent elements – one of which, was the previously never before seen element
1523:
Indeed, Fermi discovered elements he did not recognise. He tested for elements below uranium in the periodic table: radon, actinium, polonium, as far back as lead – it was none of these. So, in 1934, the infallible Fermi declared to the world he had created elements heavier than uranium.
1484:
Rutherford fixed a source of alpha particles – each of which contains two protons – at one end of a cylindrical chamber. At the other end he fixed a screen. Each time an alpha particle reached the screen it produced a flash. He then introduced nitrogen into the chamber and observed
1303:
Meanwhile, in Paris, Wurtz had been slow to publish Couper's paper and Kekulé, whose work appeared in print first, claimed all the credit. When Couper discovered Wurtz had delayed in sending his paper to be published he flew into a rage and was promptly expelled from the laboratory by Wurtz.
972:
that occurred in August of that year. As well as his telescope, he also went equipped with a spectroscope, to study the spectral lines of the light emitted from the sun. Normally, due to the intensity of sunlight many weaker spectral lines are not visible next to the extreme brightness of the
520:
Lavoisier went on to give science its first definition of an element: a substance that cannot be decomposed by existing chemical means. He also set about drawing up a list of all the elements – now 33 elements replaced the ancient four. His list was grouped into four categories: gases,
504:
Lavoisier had successfully dispensed with the need for the theory of phlogiston and recognised
Priestley's 'dephlogisticated air' as the element oxygen. Despite the fact it was Priestley's original work that laid the foundations for his discovery, Lavoisier claimed he had discovered oxygen;
1085:
This theory explained why all elements react in the way they do and why some formed the compounds they do, while others did not. It also explained why elements had the physical properties they did, which in turn explained why the periodic table had the shape it did. However, there was one
660:
was one of the few scientists who strongly believed in the idea of atomic weights, and thought that knowing as much as possible about their weights was vitally important. When he heard of Dalton's theory, he set about the gargantuan task of measuring the atomic weight of every single known
1081:
The chemical behaviour of all elements is explained by the number of electrons in their outer shells: to increase the energetic stability of their electron configurations atoms have a tendency to gain or lose electrons in such a way so as to achieve a full outer shell. Sodium, with 11
342:
Boyle was willing to share his discoveries to allow others to build on his work and further the scientific understanding of the elements. He wanted to put alchemy on a more scientific footing – ditching the metaphysical baggage it had brought with it from the previous century.
1485:
additional, different flashes on the screen. Occasionally, an alpha particle would collide with a nitrogen nucleus and get absorbed by it, knocking out a proton in the process. These protons then travelled on through the chamber to the screen to produce the additional flashes.
1299:
was a German scientist who spent some time studying in London. It was apparently whilst riding a London bus he struck upon the idea of atoms 'holding hands' to form long chains. Kekulé rushed to compose a paper formalising his ideas on an equivalent theory of chemical bonds.
1082:
electrons – one in its outer-most occupied shell, will transfer an electron in the presence of fluorine to its outer-most occupied shell, which contains seven electrons. The result is both sodium and fluorine now have a full outer shell, and Sodium
Fluoride is formed.
1011:
A problem now arose – Mendeleev had not left any gaps which were suitable for either of these two new elements, which led Ramsay to conclude an entire group was missing from the periodic table – only two of whose members were now known to exist, helium and argon.
1488:
However, the nucleus of nitrogen – having absorbed two protons but lost only one – had gained a proton and become a nucleus of oxygen. Rutherford's work gave hope to scientists trying to create new elements, but one final discovery about the atom was necessary.
702:. He believed the key to understanding the elements lay not with their atomic weights but with their chemical properties. He noticed that one could often single out three elements that exhibited similar properties, such as the alkali metals, which he called
1191:
Instead of backing down, Wöhler challenged von Liebig to make silver cyanate for himself. The results would have astounded him – the same elements that combined according to von Liebig's method, when combined according to Wöhler's method made two
1103:. When measured, the x-rays always had the same energy, unique to copper. He discovered each element released x-rays of different energies. Moseley's brilliance was to realise the x-ray energy is related to the number of protons inside the atom: the
1515:
Fermi reasoned that because neutrons carried no electric charge, they would have a much better chance of penetrating the nucleus of a uranium atom. So Fermi set about firing neutrons at uranium. Fermi thought that this, coupled with his knowledge of
1157:
After heating the resulting solid to an ash, filtering and diluting, Diesbach added green vitriol (iron sulphate) to create a complex ion: ferric ferrocyanide. Finally, adding spirit of salt (hydrochloric acid) draws out a brilliant colour:
1592:
For an explosion to occur, there must be a rapid release of energy – a slow release of energy from uranium nuclei would give a uranium fire, but no explosion. Both sides poured their effort into creating the necessary conditions for a
364:. The idea was that phlogiston causes things to burn, reducing them to their pure form. For example, burning wood releases phlogiston, leaving the pure form of wood – ash, therefore wood is composed of ash (pure wood) and phlogiston.
1602:
In 1942 Enrico Fermi, now living in America, successfully induced a chain reaction in uranium, but processing uranium for bombs was both difficult and costly. America had just come up with a different solution to win the atomic race.
1229:
was experimenting on diamonds when he decided to burn one. Using only sunlight and a magnifying glass he managed to ignite a diamond sufficiently for it to produce a gas, which he collected and was able to identify as carbon dioxide.
1476:
Rutherford realised that if an atom is losing protons, its identity is changing at the same time, since an atom's identity is governed by its proton number. Radioactive decay causes atoms of one element to transmute into atoms of a
689:
However, by the time Berzelius had produced his results, other scientists were now measuring atomic weights – and getting conflicting results. In fact, scientists were looking for all sorts of patterns throughout the elements.
1403:
crystals when he found UV light made them glow. Leaving the uranium crystals on an unexposed photographic plate overnight, he returned the next morning to discover they had caused the part of the plate they were sat on to develop.
890:
knew that when certain elements burned in the flames of his burner they each turned the flame a different colour. Copper burned green, strontium red and potassium lilac – Bunsen wondered if every element had a unique colour.
664:
This was even more challenging than it first seems once you consider the fact that very little of the chemical glassware necessary for such precise measurements had been invented. Berzelius had to manufacture much of it himself.
390:) and collected the evanescence given off as bubbles. The gas he collected was tasteless, odourless and colourless, and moreover it produced a squeaky pop in the presence of a flame – this led Cavendish to name the gas
826:
Mendeleev's genius was to combine those two methods together. However, the odds were stacked against him – little more than half the known elements had been discovered: he was playing with an incomplete deck of cards.
784:
noticed that when ordered by weight, every eighth element seemed to share similar properties, such as carbon and silicon in the sequence: carbon, nitrogen, oxygen, fluorine, sodium, magnesium and silicon. He called this a
1001:
was able to collect a gas trapped within the rock, which had an atomic weight of 4, and the same spectral lines which Lockyer had observed: helium. Prior to this, Ramsay had already isolated a new gas from the atmosphere;
1136:
Since prehistoric times, people have been engaging in 'bucket chemistry' – adding all sorts of chemicals together, just to see what would happen. As a result, many early discoveries in chemistry were accidental.
423:
Phlogiston had given the Ancient Greek idea of water as an element a brief reprieve, but the Greek system was now under heavy scrutiny as the Royal Society commissioned its members to investigate the invisible airs.
1431:
Curie began stockpiling tonnes of pitchblende, then in the most basic of workshops with primitive equipment she undertook a multitude of complex and dangerous procedures in an attempt to isolate this new element.
1098:
speculated that the answer to the number of protons lay in the nucleus. By firing a radioactive source at copper, he was able to knock electrons from their atoms, releasing a burst of energy in the form of an
1033:(Greek for stranger). All the elements of this new group had one overwhelming characteristic; their lack of reactivity. It was this particular characteristic that brought to mind a name for the new group: the
1216:
Chemists started to realise that understanding the arrangement of atoms within compounds was crucial if they wished to design new compounds, and the first step in this direction was taken by studying carbon.
1662:
Using one of the world's largest particle accelerators, scientists working at the Heavy Ion Research facility in Darmstadt, Germany, have so far confirmed the existence of element 112, which they have named
1307:
The crushing disappointment at having lost out on his chance of scientific recognition led him first to withdraw from Science and then to suffer a nervous breakdown. He spent years in and out of an asylum.
534:, but the nomenclature of compounds was also put on a more logical footing as 'oil of vitriol' became sulphuric acid, 'philosophical wool' became zinc oxide and 'astringent mars saffron' became iron oxide.
311:, as icy noctiluca is now known, is used in everything from match heads to toothpaste and ultimately in the Second World War bombs which destroyed the very city in which Brand discovered it – Hamburg.
1520:, whereby an unstable nucleus attempts stabilisation by converting one neutron to a proton and ejecting a newly formed electron, would result in an element with one extra proton than uranium: element 93.
647:
Although Dalton did not get all his atomic weights correct, he was pointing science in the right direction. Sadly, in the early 1800s few scientists accepted the idea that elements had different weights.
838:
474:
In October 1775 Priestley accompanied Lord Shelburne on a trip to Paris where they were invited to dine with the preeminent scientists of the time. It is here that Priestley met the French scientist
258:
Paracelsus did not succeed in convincing the establishment – instead he managed to enrage them by burning their established medical texts, and eventually had to flee Switzerland for Germany.
1113:
from one element to the next there can be no extra elements between Hydrogen (atomic number 1) and Uranium (atomic number 92) – there can only be 92 elements, there is no room for any more.
420:
However, it simply did not occur to Cavendish that water was a compound – instead he assumed that the airs contained a form of water, which phlogiston modified into liquid, elemental water.
1618:
machines. This involved using huge magnets to steer atoms round in circles faster and faster until they reached a tenth of the speed of light, whereupon they were smashed into a uranium target.
1428:
with an electrometer. She discovered it was four times more radioactive than pure uranium, and wondered if this was due to the presence of an even more radioactive element in the pitchblende.
1335:
successfully drew off a fibre from the interface of two liquids: hexane-1,6-diamine and decanedioyl-dichloride, which could be spun into a very fine, very strong thread. It was given the name
1344:
Shockingly, only three weeks after the patent for nylon had been filed, a depressed Carothers slipped another carbon based compound into his own drink, potassium cyanide, and killed himself.
1367:
experimented with a myriad of different compounds, which he added to petrol in an attempt to prevent engines from knocking. Eventually, he discovered one compound that worked brilliantly:
537:
Unfortunately, whilst Lavoisier had rid the world of the phlogiston paradigm, he introduced two new erroneous elements now known to be pure energy: lumière and calorique; light and heat.
976:
The eclipse allowed Janssen to observe a spectral line never seen before, which was not associated with any known element. The same spectral line was confirmed by the English astronomer
1643:, quickly followed in 1941, which scientists realized was readily able to undergo fission in a way capable of producing the desired chain reaction. It was soon being made into a bomb.
740:
At the time the scientific community was grappling with the problem of how to bring order to the 63 elements that were now known. Mendeleev was still a student when he attended the
859:
Mendeleev was sufficiently confident in the layout of his table that he was willing to leave gaps for unknown elements to make the pattern fit – believing other elements would
367:
Phlogiston was accepted as scientific truth, paralysing the scientific community's ability to discover more, true elements. One scientist even claimed to have isolated phlogiston.
461:. This was an excellent opportunity, given that Priestley did not have the money of earlier chemists like Boyle and Cavendish, and would still be free to pursue his own research.
590:
were also elements. By the time of his death in 1829 the idea of the elements was firmly established, 55 separate elements had been discovered, and the world had a new science:
278:
fragments of a substance emerged which burned brighter than any Medieval candle available at the time, but which left the vessel it burnt in cold: Brand named this new substance
314:
Whilst Brand never discovered gold, his accidental discovery of the element now known as phosphorus gave rise to the idea that elements could be hidden inside other substances.
1646:
A mere seven years after the discovery of nuclear fission, on 6 August 1945, half a gram of uranium was converted into energy when the world's first atomic bomb was dropped on
1672:
These physicists have become the new chemists – testing the foundations of the periodic table, and hence our understanding of the universe, in light of new discoveries.
403:. This should have had enormous repercussions for the whole scientific community in the 1700s, who still believed water to be an elemental substance. Yet, if water could be
1280:
In graphite only three bonds are connected to other carbon atoms in a two-dimensional hexagonal lattice, allowing layers to slide over each other, making graphite soft.
1376:
By the 1970s the use of leaded petrol was ubiquitous worldwide, but research was emerging about the damage that it was doing to humans and the environment. In 1983, a
303:
describes an experiment in which sulphur and phosphorus powders are mixed causing them to burn fiercely. This discovery was the basis for the invention of the match.
956:
Even though Mendeleev had left the necessary gap for gallium as well as other elements, it was becoming clear there was an entire group that was missing altogether.
524:
On top of this, Lavoisier created a classification system for the ever-increasing array of chemicals being discovered. As mentioned, 'dephlogisticated air' became
1176:, had become obsessed with trying to better understand the elements by creating explosive combinations. Specifically, he was interested in the explosive compound
796:, unfortunately for Newlands, the musical analogy was not well received – the audience suggesting he might as well have ordered the elements alphabetically.
1790:
450:, a Unitarian minister whose favourite pastime was the investigation of airs – specifically, fixed air, given off by the fermentation process in breweries.
399:
Cavendish, though he did not realise it, made an important observation about burning phlogiston in air; a dewy liquid was formed on the inside of the glassware:
1555:
Over Christmas 1938, Meitner considered the problem of the uranium nucleus, which she reasoned, given its relative size, must be quite unstable. She decided to
1559:, ready to divide with the impact of a single neutron. She realised the nucleus had split in half, and both Fermi and Hahn had witnessed what is now known as
224:
The Ancient Greeks, with no way of breaking open substances, could only base their ideas of the elements on what they could see: Earth, Fire, Water and Air.
1770:
1347:
Evidently, industrial chemistry wasn't without its downsides, and one chemist was arguably responsible for single-handedly polluting the entire Earth with
1240:
Unaware of atomic theory at the time, scientists were unable to explain how carbon, already known to exist as one of the softest substances in the form of
1311:
However, now that scientists were beginning to understand the way carbon combines with itself and other elements, it was possible to create new compounds
1116:
Moseley was just 26 when he completed this research. Aged 27 he was killed in action during the First World War – shot through the head by a sniper.
1795:
1775:
879:
So, for Mendeleev to be vindicated, the gaps needed to be filled, and luckily, in 1859, new instrumentation had been developed for discovering elements.
721:
In 1848 a huge fire destroyed the factory of the widow Maria Mendeleeva. Facing destitution she decided to embark on the 1,300 mile journey from Western
1233:
Having started with only diamond and oxygen, and produced a gas which contains only carbon and oxygen, Tennant had discovered that diamonds are made of
668:
Berzelius' experiences with glass-blowing had an additional bonus, in 1824 he discovered that one of the constituents of glass was a new element –
1800:
1086:
fundamental question left unanswered: how many elements were there – could there be an infinite number of elements between Hydrogen and Uranium?
516:, 2 vols. Chez Cuchet, Paris (1789). Translated from the French by Robert Kerr, Elements of Chemistry, 4th edition. William Creech, Edinburgh: (1790).
335:
was innovative in several ways: it was not written in Latin, as had been the tradition for alchemist books, but in English; it dispensed with the old
902:, a device with a prism at its centre which split the light from Bunsen's flames into distinct bands of its constituent colours – the element's
1273:. Somehow, Couper realised that carbon can form four bonds, thereby attaching itself with different strengths to other carbon atoms in a compound:
1467:
change – through a process of decay where parts of the nucleus are ejected from the atom. Rutherford named these fragments of ejected nucleus
1267:. Whilst in Paris he came up with the idea of links between atoms that could explain how individual atoms formed compounds. He called these links
1765:
1556:
1760:
1650:. As Lisa Meitner's calculations suggested, this conversion released energy equivalent to 13,000 tons of TNT. A plutonium bomb was dropped on
557:
because he was unconvinced potash was an element, but by the end of the previous century, Lavoisier had been unable to break it down further.
1536:, decided to investigate Fermi's bold claim. Unfortunately for Fermi, they quickly disproved his assertion; one of the elements produced was
911:
Kirchhoff and Bunsen realised these spectral lines were unique to each element, and, using this technique they discovered two new elements,
830:
He stayed up for three days and nights then, finally, on 17 February 1869, he fell asleep and dreamt of all 63 known elements laid out in a
1628:
blasted uranium with a beam of particles to create the first synthetic element, heavier than uranium – element 93, which they named
624:
Scientists had recently discovered that when elements combine to form compounds, they always do so in the same proportions, by weight.
1070:
proposed the structure of the atom was like that of a solar system: mostly empty space with electrons floating around a dense nucleus.
1455:
At the beginning of the 20th century it was widely believed that atoms never change: an atom of one element stayed that way forever.
860:
1407:
Becquerel correctly reasoned the only source of energy that could have caused this was the crystals themselves. He had discovered
973:
stronger lines. Janssen hoped that he would observe more spectral lines during the eclipse when the sun's light was less intense.
1447:. Whilst these were naturally occurring elements, they fuelled a scientific desire to create entirely new, artificial elements.
197:
1780:
339:
for various elements, using English names instead; and most crucially it was actually published, as opposed to kept secret.
331:
in its vaults. This book is usually regarded as the turning point that signaled the transition from alchemy to chemistry.
1129:
Just 92 elements combine to form all the compounds on Earth. Iron, when combined with chromium, carbon and nickel makes
1606:
Now finally, scientists' dream of creating an element beyond the end of the periodic table was about to be realized.
1213:
compounds. In time, this would explain how just 92 elements could make the vast array of compounds we know today.
856:
Notice carbon and silicon are in Group IV and the volatile gases fluorine, chlorine and bromine are in Group VII.
261:
It was, however, the alchemical pursuit for gold that led to the first breakthrough in the hunt for new elements.
240:
1380:
asked the question: "Is there any part of the Earth’s surface, or any form of life that remains uncontaminated?"
928:
628:
thought that for this to happen, each element had to be made of its own unique building blocks, which he called
383:
was a painfully shy character, who made the vital chemical contribution of discovering the first elemental gas.
1810:
1251:
Exactly 50 years later, a young Scottish chemist discovered there are no prizes in Science for coming second.
1785:
781:
871:
After Zinc (Zn, weight 65) he left a gap, predicting a metal with a low melting point and atomic weight 68;
867:
After Calcium (Ca, weight 40) he left a gap, predicting a metallic element slightly heavier than calcium;
358:
proposed that fire was caused by an ethereal, odourless, tasteless, colourless, weightless entity called
285:
Soon after its discovery, icy noctiluca toured the Royal Houses of Europe and in 1677 it came before the
1540:, which, with 56 protons, was nowhere near the 92 protons the nucleus started with when it was uranium.
1277:
In diamond all four bonds are connected to other carbon atoms in three-dimensions, making it so hard.
578:
Davy went on to add six new elements to Lavoisier's list, as well as confirming that substances like
1805:
1570:
1500: – electrically neutral particles which also sit inside the nucleus along with the protons.
898:. Kirchhoff used the concept of the dispersion of white light by a prism in the invention of the
875:
Immediately after that gap, he left a further gap, predicting another metal, dark grey in colour.
657:
1260:
710:
760:
proposed measuring the densities of gases to measure the weights of individual gaseous atoms.
1264:
465:
it burn, therefore the gas must be 'without phlogiston' – this led Priestley to name it
355:
327:
290:
1316:
756:
467:
325:
More than a decade earlier in 1661, a year after the Royal Society opened, Boyle deposited
189:
1692:
The full series was released as a region 2 DVD set in 2015 by the Dutch company B-Motion.
1609:
699:
549:
In 1807, the Professor of Chemistry at the Royal Institution in London was the Cornishman
227:
In the 16th century alchemists were busy trying to turn base metals like lead, into gold.
8:
1614:
In California, scientists were trying to create a new element heavier than uranium using
1015:
Ramsey successfully discovered all the other stable elements in the group which he named
989:
However, it wasn't long before another British scientist had discovered helium on Earth.
713:
only worked for a few of the elements and got scientists no further than atomic weights.
1733:
1296:
1184:
1708:
1364:
741:
34:
1463:
Rutherford came to the conclusion that the number of protons in a radioactive element
1745:
1625:
1586:
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1332:
1173:
1150:
1067:
931:
used a spectroscope to discover a new metallic element. It was a silvery-white, soft
837:
475:
413:
387:
346:
Unfortunately, this new age of chemical enlightenment was fraught with blind alleys.
218:
845:
Mendeleev's table reveals the relationship between all the elements in their order:
1377:
1226:
895:
793:
730:
447:
336:
251:
amongst which was the idea that the world was actually made of three elements: the
214:
1561:
1503:
1469:
1396:
1384:
1254:
1130:
949:, thus matching all the expected properties of the element Mendeleev expected to
392:
380:
376:
1291:
841:
Dmitri Mendeleev's periodic table from 1871 with gaps (-) left for new elements.
1621:
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where each element was represented by an alchemical-looking symbol, ordered by
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44:
953:; indeed, this is exactly where the element was placed in the periodic table.
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element. He then sought to artificially engineer a specific transmutation.
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reverse was also true: an electric current could cause a chemical reaction.
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on grounds of being an enemy of the French people, and had him guillotined.
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By their chemical properties (Döbereiner's Triads and Newland's Octaves).
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had absorbed something from the air, making it heavier, but if so, what?
1739:
1684:
It aired in the United States under the title "Unlocking the Universe."
1729:
1610:
Edwin McMillan and Philip H. Abelson create the first synthetic element
1517:
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element – without any proof that Dalton's atoms actually existed.
360:
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By their atomic weights (Berzelius' and Cannizzaro's Atomic Weights);
772:
744: – convened to settle the confusion surrounding atomic weights.
729: – walking a significant portion of the route – so her son
571:
1547:
who, as an Austrian Jew, had recently fled Nazi Germany for Sweden.
1354:
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922:
1651:
1437:
1328:
1241:
683:
674:. Having already discovered three other elements prior to silicon:
580:
530:
505:
Priestley, after all, had failed to recognise it as a new element.
146:
815:
To date, chemists had tried to group elements in one of two ways:
651:
1400:
1245:
1146:
1023:
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722:
675:
670:
1172:
Ever since seeing fireworks as a child, another German chemist,
1537:
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1387:, although lead lives on in motor vehicles in their batteries.
1288:
All that remained for Couper was to get his paper published...
982:
882:
752:
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1504:
Enrico Fermi claims to have made elements heavier than uranium
1255:
Archibald Scott Couper formulates the theory of chemical bonds
481:
1337:
1292:
Friedrich Kekulé formulates the same theory of chemical bonds
1100:
1029:
1004:
980:, who thinking the element only existed in the sun, named it
400:
748:
Stanislao Cannizzaro's standard for measuring atomic weights
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New Experiments and Observations Made Upon the Icy Noctiluca
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is – a substance that cannot be broken down further by
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Justus von Liebig and Friedrich Wöhler encounter isomerism
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Three years later, in 1866, he presented his ideas to the
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began her investigations by testing a uranium ore called
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In 1526 Paracelsus was in Basel, when the famous printer
185:
131:
1569:
solution to this discrepancy occurred to Meitner –
1285:
carbon exists in more compounds than any other element.
945:, after his native France. It also turned out to have a
852:
Triads and Octaves are visible reading down the columns.
453:
Priestley's passion for science led to an invitation to
1576: – the missing mass had been converted to energy.
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370:
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1550:
1527:
1413:, and a young Polish scientist began to investigate.
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1221:
Smithson Tennant discovers what diamonds are made of
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Heinrich Diesbach produces the first synthetic paint
997:
By dissolving the radioactive ore cleveite in acid,
1327:Two decades after the world's first plastic –
1199:Wöhler and von Liebig had inadvertently discovered
849:
Atomic weights increase reading from left to right;
803:, and Mendeleev was thinking along the same lines.
733:could continue his education in the capital of the
446:It was this last air which caught the attention of
293:, where one of its members decided to investigate.
1322:
1188:exactly what made the explosive silver fulminate.
512:Table from the English translation of Lavoisier's
1679:
1435:In the event, Curie discovered two new elements,
1355:Thomas Midgley Jr. prevents engines from knocking
1089:
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960:Pierre Janssen and Norman Lockyer discover helium
923:Paul Emile Lecoq de Boisbaudran discovers gallium
812:form a pattern where everything fitted together.
213:Only in the last 200 years have we known what an
1752:
1205:: the same number of atoms of the same elements
432:By the mid-1700s there were three known 'airs':
230:
1669:, after Polish astronomer Nicholas Copernicus.
776:Visualization of John Newlands' Law of Octaves.
652:Jöns Jacob Berzelius' pursuit of atomic weights
349:
239:who first challenged the Ancient Greek idea of
1791:Documentary films about the history of science
742:world's first international chemistry congress
1543:Hahn wrote of his confusion to his colleague
1532:In 1938, a team of German scientists, led by
806:
693:
883:Bunsen's burner and Kirchhoff's spectrometer
620:Dalton's atomic symbols, from his own books.
553:. He was investigating crystalline salts of
1771:2010s British documentary television series
1658:GSI Helmholtz Centre for Heavy Ion Research
698:One such pattern hunter was German chemist
482:Antoine Lavoisier and the end of phlogiston
1796:BBC television documentaries about science
1776:BBC television documentaries about history
1732:
799:Today, Newlands' Octaves are known as the
544:
407:by burning inflammable air, then water is
289:in London, then under the chairmanship of
1801:British English-language television shows
1589:aimed at creating the first atomic bomb.
968:travelled to India in time for the total
767:
428:Joseph Priestley and dephlogisticated air
1579:
1460:atom with 7 protons is one of nitrogen.
1451:Ernest Rutherford explains radioactivity
993:William Ramsay discovers the noble gases
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1391:Henri Becquerel discovers radioactivity
1133:. Glass is made of silicon and oxygen.
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717:Dmitri Mendeleev moves to St Petersburg
235:It was the Swiss alchemist and surgeon
1766:2010 British television series endings
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1417:Marie Curie investigates radioactivity
611:
386:He added some zinc to spirit of salt (
255:comprising salt, sulphur and mercury.
198:2010 British Academy Television Awards
1761:2010 British television series debuts
894:Bunsen was joined in his research by
436:Common air – the air we breathe;
1557:model the nucleus as a drop of water
1359:In his capacity as an engineer with
1120:Episode 3: The Power of the Elements
598:Episode 2: The Order of the Elements
273:was looking for a way of extracting
200:in the category Specialist Factual.
1331: – had been invented in 1907,
1263:went to work for a French chemist,
1183:In 1825 he read a paper written by
1078:an increasing number of electrons.
1073:Subsequently, the Danish Physicist
951:fill the gap he had left after zinc
371:Henry Cavendish and inflammable air
204:Episode 1: Discovering the Elements
13:
1551:Lise Meitner explains Fermi's work
1528:Otto Hahn disproves Fermi’s claims
1441:named after her native Poland and
265:Hennig Brand and the icy noctiluca
14:
1822:
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1492:In 1932 the Cambridge scientist
1154:haemoglobin to produce a solid.
1676:mercury in the periodic table.
1323:Wallace Carothers invents nylon
1008:, with an atomic weight of 40.
964:In 1868, the French astronomer
929:Paul Emile Lecoq de Boisbaudran
521:non-metals, metals and earths.
208:
1702:
1680:Broadcast in the United States
1194:completely different compounds
1090:Henry Moseley's proton numbers
1062:Niels Bohr's fixed shell model
927:In 1875, the Parisian chemist
560:Since then however, the first
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1741:Chemistry: A Volatile History
1725:Chemistry: A Volatile History
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1395:In 1896 the French scientist
354:In 1667 the German scientist
231:Paracelsus and the tria prima
181:Chemistry: A Volatile History
25:Chemistry: A Volatile History
1781:Historical television series
1637:The next synthetic element,
514:Traité élémentaire de chimie
439:Cavendish's inflammable air;
350:Johann Becher and phlogiston
282: – 'cold night light'.
7:
1383:Today nearly all petrol is
1207:combining in different ways
1094:Early 20th century chemist
986:, after the Greek Sun God.
528:, 'inflammable air' became
457:, to tutor the children of
375:A major shareholder in the
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545:Humphry Davy and potash
1261:Archibald Scott Couper
947:very low melting point
863:that filled the gaps.
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768:John Newlands' octaves
656:The Swedish scientist
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1811:Films about chemistry
1580:The Manhattan Project
1265:Charles-Adolphe Wurtz
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709:The problem was that
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333:The Sceptical Chymist
328:The Sceptical Chymist
320:The Sceptical Chymist
1786:History of chemistry
1688:Region 2 DVD release
1317:industrial chemistry
1043:Mendeleev vindicated
757:Stanislao Cannizzaro
658:Jöns Jacob Berzelius
468:dephlogisticated air
190:history of chemistry
16:2010 BBC documentary
937:atomic weight of 68
861:later be discovered
711:Döbereiner's triads
612:John Dalton's atoms
188:documentary on the
1654:three days later.
1365:Thomas Midgley Jr.
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801:Law of Periodicity
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411:an element, but a
128:Production company
112:Executive producer
35:History of science
1626:Philip H. Abelson
1587:Manhattan Project
1399:was working with
1333:Wallace Carothers
1174:Justus von Liebig
1151:Heinrich Diesbach
1068:Ernest Rutherford
1021:(Greek for new),
939:, which he named
700:Johann Döbereiner
476:Antoine Lavoisier
388:hydrochloric acid
318:Robert Boyle and
219:chemical reaction
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1297:Friedrich Kekulé
1227:Smithson Tennant
1185:Friedrich Wöhler
1178:silver fulminate
1145:In 18th century
896:Gustav Kirchhoff
794:Chemical Society
731:Dmitri Mendeleev
562:electric battery
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337:chemical symbols
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279:
271:Hennig Brand
268:
260:
257:
252:
245:
234:
226:
223:
212:
209:Introduction
180:
179:
178:
120:Running time
55:Andrea Sella
41:Presented by
24:
18:
1709:tvtango.com
1666:copernicium
1426:pitchblende
1422:Marie Curie
1051:mendelevium
1036:noble gases
832:grand table
626:John Dalton
99:of episodes
61:Narrated by
1755:Categories
1730:BBC Online
1696:References
1518:beta decay
1457:Rutherford
1319:was born.
1075:Niels Bohr
608:elements?
442:Fixed air.
361:phlogiston
308:Phosphorus
291:Charles II
253:tria prima
237:Paracelsus
184:is a 2010
170:2010-02-04
160:2010-01-21
156:21 January
123:60 minutes
107:Production
1648:Hiroshima
1640:plutonium
1631:neptunium
1616:cyclotron
1534:Otto Hahn
1479:different
1313:by design
1211:different
1202:isomerism
592:Chemistry
572:potassium
248:Frobenius
88:of series
1652:Nagasaki
1438:polonium
1385:unleaded
1329:Bakelite
1259:In 1856
1242:graphite
1225:In 1796
1209:to make
935:with an
917:rubidium
780:In 1863
755:chemist
753:Sicilian
684:selenium
581:chlorine
531:hydrogen
414:compound
269:In 1669
147:BBC Four
72:Ty Unwin
69:Composer
51:Starring
1498:neutron
1401:uranium
1246:diamond
1147:Prussia
1024:krypton
942:gallium
723:Siberia
676:thorium
671:silicon
215:element
168: (
164: –
158: (
153:Release
143:Network
80:English
1573:E = mc
1538:barium
1444:radium
1235:carbon
983:helium
913:cesium
704:triads
680:cerium
587:iodine
555:potash
526:oxygen
498:oxygen
1465:could
1338:nylon
1270:bonds
1101:x-ray
1048:him:
1030:xenon
1005:argon
933:metal
631:atoms
401:water
31:Genre
1746:IMDb
1624:and
1349:lead
1315:and
1018:neon
915:and
682:and
584:and
405:made
275:gold
1744:at
1728:at
725:to
409:not
186:BBC
132:BBC
97:No.
86:No.
1757::
1634:.
1599:.
1565:.
1473:.
1373:.
1363:,
1351:.
1341:.
1248:.
1237:.
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1180:.
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1149:,
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678:,
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162:)
102:3
91:1
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