The hunt for elements has changed greatly throughout the years. At the beginning of humanity's search, unreactive elements were simply ‘found’ (very unreactive elements can be found in the ground). If they are common enough, elements will be found in clumps, like copper. Copper was the first element to be found, and although the date of its discovery is not recorded, it is thought to have been discovered around 9,000 years BC. However, the people who found it would not have understood the principle of an element, and so had no idea of the significance.
Scientists claimed to have found new elements throughout history until the late 1700s, but without a theory to follow it is hard to say whether they ‘knew’ what they were looking for, or where they were looking for it. They simply hoped they had found pure substances which could not be broken down, as they didn’t really understand what they were looking for, and therefore I believe they were looking for glory rather than actual scientific discovery.
The first man to list elements and truly see them as elements was Antoine Lavoisier, a French chemist who created a list of what he believed to be all the known elements (he was also the first man to define an element, which started the race to find elements). Unfortunately, not that he could have known, his list was inaccurate. The list contained many substances which were not elements; caloric, for example, was an element he believed contained heat and moved from hotter places to colder so giving the property of heat. Lavoisier's list also contained radicals of 19 organic acids, 3 alkali and 5 earth metals. For all its downfalls, it contained 17 metals and the idea of carbon, hydrogen, oxygen and nitrogen. It was a start and the hunt for elements has not stopped since.
The hunt for elements at this time - 1750-1850 - was more like a mad scramble than a hunt, with no one really knowing what to look for or where they might find it; most elements were found by splitting up minerals. In these early days, for every correct element there were multiple incorrect ‘elements’, with no definite way of proving some things were or were not elements. Following the theories of Lavoisier, Martin van Marum introduced modern chemistry to the Netherlands. He took salts and reduced them, creating elements by using electrolysis: in this way he discovered tin, zinc and antimony in one of the early examples separating compounds into pure samples.
Russian, Dmitri Mendeleev, was probably the most visionary chemist ever to live, single handedly creating the periodic table about 150 years ago, with limited knowledge; even today it is seen as the best way to store the elements. His genius was to take full note of periodicity (trends between elements, chemical and physical changes or similarities) and also atomic mass and, when lined up, the layers fell into place. Another key attribute to his table was that he was not scared to leave huge gaps in the table, knowing that the elements simply had not been discovered yet. He then predicted what should have been in the place, where an element with certain properties were missing. This led to a recognisable debate …
Paul Emile Lecoq de Boisbaudran was a Frenchman born in 1838 and was known for his ‘discovery’ of gallium, which he first observed by seeing certain colour bands in minerals. He made a sample and published his results, only for Mendeleev to get in touch and tell him that he had in fact predicted gallium and so deserved credit, and also that, although the Frenchman had found gallium, he had made mistakes; the density of the metal the Frenchman found, was wrong compared to the Russians predictions. Mendeleev was right and Boisbaudran retracted his results. It was astounding that at this time theory had overtaken practice such that elements’ properties could be predicted more accurately than purified and measured. From this point forward, scientists knew exactly what they were looking for: they just had to find it. Another interesting story surrounding gallium is the naming of it, it is taboo to name an element after one’s self; it should be named after a fellow scientist or in this case a country, Boisbaudran named gallium after the Latin for France Gaul. Or did he? Many believe he named it after his middle name Lecoq ‘the rooster’ or in Latin ‘gallus’; whatever the case he received a fair bit of tutting from the chemical world for that.
From then, elements were found by chemists in similar ways until the physicists took over and elements were ‘made’ not found; a known element would be bombarded with particles, in the hope it would take on these particles to make a bigger element. In 1949 the University of California at Berkeley were the best at this, making Berkelium and Californium in consecutive years and working hard to make a third. The joke being, they were going to call it ‘Universitium’ such that, in the ultimate ego boost, the periodic table would read, Berkelium Californium Universitium. Sadly, when they duly found it, it was named Einsteinium. Who says chemists don’t have a sense of humour?
The element hunt continues to this day, with the number of elements either made up or found at 118.
Original image used