In the late 19th century, Russian chemist Dmitri Mendeleev published his first attempt at grouping chemical elements according to their atomic weights. There were only about 60 elements known at the time, but Mendeleev realized that when the elements were organized by weight, certain types of elements occurred in regular intervals, or periods. Today, 150 years later, chemists officially recognize 118 elements (after the addition of four newcomers in 2016) and still use Mendeleev's periodic table of elements to organize them. The table starts with the simplest atom, hydrogen, and then organizes the rest of the elements by atomic number, which is the number of protons each contains. With a handful of exceptions, the order of the elements corresponds with the increasing mass of each atom. The table has seven rows and 18 columns. Each row represents one period; the period number of an element indicates how many of its energy levels house electrons. Sodium, for instance, sits in the … [Read more...] about How Are Elements Grouped in the Periodic Table?
Periodic table of elements
On Feb. 17, 1869, Russian chemist Dmitri Mendeleev published his first attempt to sort the building blocks of life into orderly groups. Now, 150 years later, we know the fruits of his labor as the Periodic Table of Elements — a quintessential piece of classroom wall art and indispensable research tool to anyone who's ever picked up a beaker. As you can see for yourself in the hand-scrawled draft above, Mendeleev's first table looked very different than the one we know today. In 1869, only 63 elements were known (compared with the 118 elements we have identified today). As a student at Heidelberg University in Germany and later as a professor at St. Petersburg University, Mendeleev realized that by grouping elements according to their atomic weights, certain types of elements periodically occurred. [Elementary, My Dear: 8 Little-Known Elements] Mendeleev honed this "periodic system," as he called it, by writing down the names, masses and properties of each known element on a set … [Read more...] about Mendeleev’s Periodic Table Draft Is Virtually Unrecognizable — But It Changed Science Forever
Oxygen can breathe easy, but the party might soon be over for helium balloons. Those are two takeaways from a brand-new model of the periodic table of elements, debuted this week by the European Chemical Society (or EuChemS, a group representing more than 160,000 chemists in the European Union). Unlike the ubiquitous classroom version of the table, which categorizes the universe's 118 known natural and synthetic elements with equal space for each element, EuChemS' chart has been warped and wobbled to show the relative abundance or scarcity of 90 naturally occurring elements here on Earth. [Elementary, My Dear: 8 Little-Known Elements] The bubbly new chart of life's building blocks is more than a cool curiosity; according to EuChemS president David Cole-Hamilton, it's also an important reminder of which of Earth's elements are in danger of disappearing, thanks to human overuse. "Some of these elements, we have less than a hundred years before it's much more difficult to get hold of … [Read more...] about Europe’s ‘New’ Periodic Table Predicts Which Elements Will Disappear in the Next 100 Years
The periodic table of elements is a familiar sight to anyone who's ever sat in a chemistry classroom — and apparently, that's been the case for nearly 150 years. Conservators at the University of St. Andrews in Scotland announced the discovery of what they say is the world's oldest surviving example of a classroom periodic table of elements, dating to 1885. The old classroom poster, printed in German on linen-backed paper, was discovered in 2014 while staffers from the university's School of Chemistry were cleaning out their storage room, according to a news release from the university. Among the clutter of decades-old lab equipment and chemical vials, staffers found an old cache of huge, rolled-up teaching charts. One of the scrolls contained the aforementioned periodic table — inked onto paper so old that it started to crumble at the touch. School records showed that the chart was purchased in Vienna by a St. Andrews chemistry professor in 1888, and the table likely … [Read more...] about World’s Oldest Periodic Table Poster Turns Up in Scottish Storeroom
caption The Table of Disruptive Technologies. source Imperial College London Academics at Imperial Tech Foresight have created a periodic table of mind-blowing tech. The table is designed to be a visual conversation starter about where the world is going. It features 100 innovations, ranging from the benign and everyday, to the mind-blowing and potentially terrifying. Academics at Imperial Tech Foresight (ITF), an offshoot of Imperial College London, have been working to bring to life nebulous and intangible technological advances in a way you’ve never seen before. They have created a table of disruptive tech, taking inspiration from the periodic table of chemical elements. It contains 100 innovations, ranging from the benign and everyday, to the mind-blowing and potentially terrifying. To give you an example, cryptocurrencies (identified as Cr) are now part of our modern life, while battlefield robots (Br) sounds like something straight out of … [Read more...] about Academics created a periodic table of mind-blowing tech, and it’s a handy guide to how the world will change forever