Periodic Table of Elements (International Union of Pure and Applied Chemistry)
Interactive Periodic Table of Elements (Los Alamos National Laboratory)
Periodic Table (American Chemical Society)
These are organized by a classification scheme developed exclusively for Cosma. More…
Periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties, whose structure shows periodic trends. Generally, within one row (period) the elements are metals to the left, and non-metals to the right, with the elements having similar chemical behaviours placed in the same column. Table rows are commonly called periods and columns are called groups. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals.
The organization of the periodic table can be used to derive relationships between the various element properties, but also the predicted chemical properties and behaviours of undiscovered or newly synthesized elements. Russian chemist Dmitri Mendeleev was the first to publish a recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts proved to be correct. Mendeleev’s idea has been slowly expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The modern periodic table now provides a useful framework for analyzing chemical reactions, and continues to be widely used in chemistry, nuclear physics and other sciences.
All the elements from atomic numbers 1 (hydrogen) through 118 (oganesson) have been either discovered or synthesized, completing the first seven rows of the periodic table. The first 98 elements exist in nature, although some are found only in trace amounts and others were synthesized in laboratories before being found in nature. Elements 99 to 118 have only been synthesized in laboratories or nuclear reactors. The synthesis of elements having higher atomic numbers is currently being pursued: these elements would begin an eighth row, and theoretical work has been done to suggest possible candidates for this extension. Numerous synthetic radionuclides of naturally occurring elements have also been produced in laboratories. — Wikipedia
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- New nanowire architectures boost computers'...on October 15, 2021 at 2:53 pm
Valerio Piazza is creating new 3D architectures built from an inventive form of nanowire. His research aims to push the boundaries of miniaturization and pave the way to more powerful electronic devices. He has just won the 2020 Piaget Scientific Award, whose prize money will fund his work at EPFL for a year.
- The remarkable variability of actinide...on October 8, 2021 at 12:48 pm
Scientists have synthesized tetrafluoride powders of four radioactive elements—thorium, uranium, neptunium, and plutonium. These four elements are actinides, a series of heavy and radioactive elements. Tetrafluoride powders are simply powders with four fluoride atoms per atom of actinide. In this new study, scientists probed the magnetic fields of these powders. This revealed remarkable variations in the electronic structures of the powders even though they have nearly identical crystal […]
- Researchers answer key question about electron...on September 23, 2021 at 2:08 pm
Scientists are working hard to engineer the properties of nanostructures, such as atoms and molecules, to realize efficient logic devices that can operate at the fundamental scale of matter—the scale of atoms. To make "engineering" possible at that scale, researchers have to be able to look at the internal structure of an atom, the so-called orbital structure, where electrons are confined in a series of shells.
- New AI tool accelerates discovery of truly new...on September 21, 2021 at 9:00 am
Researchers at the University of Liverpool have created a collaborative artificial intelligence tool that reduces the time and effort required to discover truly new materials.
- Part of the universe's missing matter foundon September 16, 2021 at 12:57 pm
Galaxies can receive and exchange matter with their external environment thanks to the galactic winds created by stellar explosions. Via the MUSE instrument from the Very Large Telescope at the ESO, an international research team, led on the French side by the CNRS and l'Université Claude Bernard Lyon 1, has mapped a galactic wind for the first time. This unique observation, which is detailed in a study published in MNRAS on 16 September 2021, helped to reveal where some of the universe's […]
- New cerium superhydrides become stepping stones...on September 13, 2021 at 12:41 pm
Researchers from Skoltech and their colleagues from China have experimentally shown superconductivity in cerium superhydrides CeH9 and CeH10, pointing the way to lower-pressure and potentially room-temperature superconductors. The paper was published in the journal Physical Review Letters.
- High-throughput method of identifying novel...on September 13, 2021 at 12:30 pm
Coupling computer automation with an ink-jet printer originally used to print T-shirt designs, researchers at Caltech and Google have developed a high-throughput method of identifying novel materials with interesting properties. In a trial run of the process, they screened hundreds of thousands of possible new materials and discovered one made from cobalt, tantalum, and tin that has tunable transparency and acts as a good catalyst for chemical reactions while remaining stable in strong acid […]
- Five reasons video games should be more widely...on September 3, 2021 at 2:10 pm
In an effort to curtail how much time young people spend playing video games, China has banned students from playing them during the school week and limits them to just one hour per day on Fridays, weekends and holidays.
- Breakthrough in actinide metal-metal bondingon August 24, 2021 at 12:21 pm
Scientists from The University of Manchester have managed to successfully make actinide metals form molecular actinide-actinide bonds for the first time, opening up a new field of scientific study in materials research.
- Making nylon 6-6 'greener,' and without zincon August 22, 2021 at 12:53 pm
Outdoor stadium seats, ski bindings, tire reinforcements and other products that require strength, durability and weather resistance are all made with a type of nylon called nylon 6-6. However, producing this material requires an environmentally unfriendly process, the first step of which uses the endangered element zinc as a catalyst. Now, researchers have developed "greener" methods for this step that use alternative metals. They might even be able to substitute waste iron in the form of […]