The elements of nature have been grouped in various ways throughout history, but it was 150 years ago that the Russian Dmitri Ivanovich Mendeleev (Tobolsk, 1834 - Saint Petersburg, 1907) presented a periodic table to bring them all togethereven those yet to be discovered.
With the contributions of other scientists this table has become the colorful heart of chemistry that we know today.
What is a chemical element?
It is the part of matter made up of atoms of the same class and that cannot be decomposed into simpler ones through a chemical reaction. Any being, living or inert, is made up of chemical elements. For example, on a mobile phone you can find around 30 different ones, and on the human body almost double: 59 elements.
So far they have been discovered and confirmed 118 chemical elements. The last four are the nihonium, moscovio, tenese and oganeson. Large laboratories from Japan, Russia, the United States and Germany compete to be the first to obtain the following: the 119 and the 120.
What is the periodic table?
It is a table where all elements are ordered by their atomic number (number of protons), an arrangement that shows periodic trends and brings together those with similar behavior in the same column.
It is a unique tool, allowing scientists to predict the appearance and properties of matter on Earth and the rest of the universe. Beyond its crucial role in chemistry, the periodic table transcends other disciplines, such as physics and biology, and has become an icon of science and culture.
How it was made?
By the middle of the 19th century, 63 elements were already known, but chemists did not agree on terminology and how to order them. To solve these questions, the first International Congress of Chemists was organized in Karlsruhe (Germany) in 1860, a meeting that would be transcendental.
There the italian Stanislao Cannizzaro clearly established the concept of atomic weight (relative atomic mass of an element), in which three young participants in the congress (William Odling, Julius Lothar Meyer and Dmitri Ivanovich Mendeleev) would be inspired to create the first tables.
Mendeleev's was the most groundbreaking when making predictions and leave gaps of elements that would be discovered later, such as the gallium (1875), the scandium (1879) and the germanium (1887). For some authors, the definitive version of the table was achieved thanks to the mathematical contributions of the British Henry Moseley.
When does Mendeleev complete his table?
The official date - taken as a reference for this year's anniversary - is the March 1, 1869 according to the Gregorian calendar, because according to the Julian calendar used in Russia at that time it would be the February 17th, as it appears in his document entitled The experience of a system of elements based on their atomic weight and chemical similarity.
Legend has it that the idea of the periodic system of the elements came to Mendeleev that day during a dream, but the Russian chemist once replied: “I've been thinking about this for 20 years, even if you think I was sitting down and suddenly ... that's it”.
Who promotes the celebration of the International Year of the Periodic Table?
The United Nations General Assembly is the one that has proclaimed 2019 as International Year of the Periodic Table of Chemical Elements (IYPT2019), managed through UNESCO. The opening ceremony will be held at its headquarters in Paris on January 29.
Among the speakers will be the British chemist Sir Martyn Poliakoff, very popular for his videos on YouTube and the one who initially proposed to organize IYPT2019 to Professor Natalia Tarasova, president of the International Union of Pure and Applied Chemistry (IUPAC).
The IUPAC, which also celebrates its own centenary in 2019, is another of the organizations that supports this initiative. Is the world authority on chemical nomenclature, the one in charge of naming the new elements of the periodic table in an official way.
Other associations that promote IYPT2019 are the International Union of Pure and Applied Physics (IUPAP), the European Association of Chemical and Molecular Science (EuCheMS), the International Council for Science (ICSU), the International Astronomical Union (IAU) and the International Union of History and Philosophy of Science and Technology (IUHPS).
What activities will take place in Spain?
They can be consulted in the events section of the Royal Spanish Society of Chemistry and, together with those of other countries, on the IYPT2019 website. Among the activities are the International Symposium on Women and the Periodic Table organized at the University of Murcia in February, various conferences and film-forums at the University of Jaén and the contest Sponsor an element aimed at high school students, vocational training cycles middle grade and 2nd cycle of ESO.
Also, Correos will release a commemorative stamp this month and the tenths of the National Lottery draw on March 2 will feature the façade of the Faculty of Chemistry of the University of Murcia, where the world's largest periodic table is located.
How many elements have Spanish scientists discovered?
Two and a half or three: tungsten or wolfram (W), platinum (Pt), and half, according to the authors, vanadium (V).
The tungsten is the only isolated element in Spain, an achievement achieved in 1783 by the brothers Juan José and Fausto de Elhuyar at the Royal Seminary of Vergara (Guipúzcoa).
Half a century earlier, the naturalist and military Antonio de Ulloa and de la Torre Giral had discovered platinum in America, in the province of Esmeraldas (Ecuador), a precious element that he described in 1748.
Finally, in 1801 the Spanish-Mexican scientist Andrés Manuel del Río Fernández found element 23 of the periodic table in a Mexican lead mine. Called him erythronium for turning reddish when heated and gave some samples to his friend Alexander von Humboldt for analysis by the French chemist H. Victor Collet-Descotils.
This, mistakenly, answered that it was a chromium compound, so he thought that his discovery was wrong.
Three decades later, in 1830, Swedish chemist Nils Gabriel Sefström rediscovered the colorful element and named it vanadium in honor of the goddess of beauty. Vanadis from Scandinavian mythology. The following year, his German colleague Friedrich Wöhler confirmed that it was the same item that Del Río had already found.
Women who discovered chemical elements
The best known is Marie Curie, a French nationalized Polish scientist who received a Nobel Prize in 1903 (in Physics) and another in 1911 (in Chemistry) for the discovery of radium (Ra) and polonium (Po), but there is more.
Austrian physicists Berta Karlik and Lise Meitner discovered, respectively, the astatine (At) and, in collaboration with other researchers, an isotope of protactinium (Pa).
For its part, German chemistry and physics Ida Noddack identified the rhenium (Re) and French physics Marguerite perey discovered the francio (Fr). Some of the activities of the International Year of the Periodic Table will remember the contributions and the example that these scientists gave.
Information prepared with the collaboration of Pascual Román, Professor of Inorganic Chemistry at the University of the Basque Country (UPV / EHU); Inés Pellón, professor of Chemistry at the UPV / EHU Bilbao School of Engineering; and Bernardo Herradón, researcher at the Institute of General Organic Chemistry of the CSIC. All three are members of the Royal Spanish Chemistry Society (RSEQ), which actively participates in the International Year of the Periodic Table.