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    Although elements such as gold, silver, tin, copper, lead and mercury have been known since earliest times, the first scientific discovery of an element occurred in 1649. Hennig Brand, a German alchemist, treated urine to a series of processes that resulted in the production of the element phosphorus.

    Over the next 200 years, a great deal of knowledge about elements and compounds was gained. By the middle of the 19th century, about 60 elements had been discovered.

    Scientists began to recognise patterns in the properties of these elements and set about developing classification schemes.

    1862

    French geologist Alexandre-Emile Béguyer de Chancourtois listed the elements on paper tape and wound them, spiral like, around a cylinder. Certain ‘threes’ of elements with similar properties came together down the cylinder. He called his model the ‘telluric screw’.

    1864

    English chemist John Newlands noticed that, if the elements were arranged in order of atomic weight, there was a periodic similarity every 8 elements. He proposed his ‘law of octaves’ on this.

    1869

    Lothar Meyer complied a periodic table of 56 elements based on a regular repeating pattern of physical properties such as molar volume. Once again, the elements were arranged in order of increasing atomic weights.

    Russian chemist Dmitri Mendeleev produced a periodic table based on atomic weights but arranged ‘periodically’. Elements with similar properties appeared under each other. Gaps were left for yet to be discovered elements.

    1894

    William Ramsay discovered the noble gases and realised that they represented a new group in the periodic table.

    1914

    Henry Moseley determined the atomic number of each of the known elements. He realised that, if the elements were arranged in order of increasing atomic number rather than atomic weight, they gave a better fit within the ‘periodic table’.

    1940

    Glenn Seaborg artificially produced heavy mass elements such as neptunium. These new elements were part of a new block of the periodic table called ‘actinides’.

    The periodic table today

    Most school science laboratories have a copy of the periodic table pinned to a wall somewhere.

    Close inspection of the table shows the following distribution of types of element.

    Most of the elements are metals. Metalloids are elements that have some of the physical properties of metals but some of the chemical properties of non-metals. Antimony, for example, conducts electricity but its chemistry resembles that of the non-metal phosphorus.

    Scientists are constantly working on discovering new materials and further investigating the properties of existing elements. The periodic table can be reviewed and new elements can be added, but only added after rigorous scientific examination. The International Union of Pure and Applied Chemistry (IUPAC) verifies the additions of new elements and at the end of 2015 the 7th period of the periodic table of elements was completed.

    Nature of science

    Science is a blend of logic and imagination. In the development of the periodic table of the elements, Mendeleev demonstrated these attributes.

    Related content

    The Science Learning Hub team has curated a collection of resources related to the periodic table of elements. Login to make this collection part of your private collection, just click on the copy icon. You can then add additional content, notes and make other changes. Registering an account for the Science Learning Hubs is easy and free – sign up with your email address or Google account. Look for the Sign in button at the top of each page.

    Useful links

    The International Union of Pure and Applied Chemistry (IUPAC) website.
    www.iupac.org

    Official announcement of the discovery and assignment of new elements with atomic numbers 113, 115, 117 and 118 in 2015.
    www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html

    BBC news article about the 4 new elements that was announced on 30 December 2015.
    www.bbc.co.uk/newsbeat/article/35221097/the-periodic-tables-new-elements-if-they-were-on-tinder

      Published 21 October 2009, Updated 5 January 2016 Referencing Hub articles