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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Stellar evolution in real time detected in the...
on August 15, 2019 at 11:08 am
An international team of astronomers succeeded in detecting signs of aging in the red supergiant star T UMi. The star in the Little Bear constellation is currently going through its last nuclear "hiccups," and will soon end its 1.2 billion year-long life.
Electronic waste is mined for rare earth elements
on August 14, 2019 at 1:20 pm
Rare earth elements are the "secret sauce" of numerous advanced materials for energy, transportation, defense and communications applications. Their largest use for clean energy is in permanent magnets, which retain magnetic properties even in the absence of an inducing field or current.
Rewriting the periodic table at high pressure
on August 14, 2019 at 12:36 pm
The periodic table has been a vital foundational tool for material research since it was first created 150 years ago. Now, Martin Rahm from Chalmers University of Technology presents a new article which adds an entirely new dimension to the table, offering a new set of principles for material research. The article is published in the Journal of the American Chemical Society.
Physicists measure how electrons in transition...
on August 5, 2019 at 4:11 pm
Researchers in the Department of Physics of ETH Zurich have measured how electrons in so-called transition metals get redistributed within a fraction of an optical oscillation cycle. They observed the electrons getting concentrated around the metal atoms within less than a femtosecond. This regrouping might influence important macroscopic properties of these compounds, such as electrical conductivity, magnetization or optical characteristics. The work therefore suggests a route to controlling […]
Turning water into ice in the quantum realm...
on August 2, 2019 at 6:00 pm
When you pop a tray of water into the freezer, you get ice cubes. Now, researchers from the University of Colorado Boulder and the University of Toronto have achieved a similar transition using clouds of ultracold atoms.
Finding alternatives to diamonds for drilling
on July 23, 2019 at 4:28 pm
Diamonds aren't just a girl's best friend—they're also crucial components for hard-wearing industrial components, such as the drill bits used to access oil and gas deposits underground. But a cost-efficient method to find other suitable materials to do the job is on the way.
Study unveils new superionic states of...
on July 16, 2019 at 10:30 am
Helium and water are known to be abundant throughout the universe, particularly in giant planets such as Uranus and Neptune. Although helium is typically unreactive at common atmospheric conditions, past studies have found that it can sometimes react with other elements and compounds under high pressure.
Fluorine speeds up two-dimensional materials...
on July 16, 2019 at 9:24 am
Back in 2004, the physics community was just beginning to recognize the existence of truly two-dimensional (2-D) material, graphene. Fast-forward to 2019, and scientists are exploring a breadth of 2-D materials to uncover more of their fundamental properties. The frenzy behind these new 2-D materials lies in their fascinating properties—materials thinned down to only a few atoms work very differently from 3-D materials. Electrons packed into the thinnest-ever layer show distinctive […]
How to discover new materials quickly
on July 10, 2019 at 1:16 pm
The number of potential new materials that can be assembled from elements in the periodic table is immense—even if researchers were to limit themselves to the 40 to 50 elements that are non-toxic, eco-friendly, and available on Earth in sufficient quantities. These possibilities remain as yet for the most part unexplored.
A virtual substrate opens path to oxide films on...
on July 10, 2019 at 1:10 pm
Proof that a new ability to grow thin films of an important class of materials called complex oxides will, for the first time, make these materials commercially feasible, according to Penn State materials scientists.