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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Stardust from red giants
on December 10, 2019 at 1:09 pm
Some of the Earth's building material was stardust from red giants, researchers from ETH Zurich have established. They have also explained why the Earth contains more of this stardust than the asteroids or the planet Mars, which are farther from the sun.
Scientist leads international team to crack...
on December 2, 2019 at 5:52 pm
A Queen's University Belfast scientist has led an international team to the ground-breaking discovery of why the Sun's magnetic waves strengthen and grow as they emerge from its surface, which could help to solve the mystery of how the corona of the Sun maintains its multi-million degree temperatures.
Physicists determine dripline for fluorine and...
on November 22, 2019 at 3:06 pm
An international team of physicists with the BigRIPS experiment taking place at the RIKEN Radioactive Isotope Beam Factory in Japan has determined the dripline for fluorine and neon isotopes. In their paper published in the journal Physical Review Letters, the researchers describe how they found the driplines and where their research is headed next.
In the Great Lakes' most productive fishing...
on November 20, 2019 at 2:58 pm
From his lakefront dock in Crystal Rock, 70 miles west of Cleveland, Dean Koch still gleefully reminisces on his career as a commercial fisherman in the heyday.
Scientists take strides towards entirely...
on November 8, 2019 at 10:00 am
Scientists from Trinity College Dublin have taken a giant stride towards solving a riddle that would provide the world with entirely renewable, clean energy from which water would be the only waste product.
Target practice: Perfecting the Mu2e production...
on November 6, 2019 at 11:39 am
Before Mu2e, there was MECO.
Magnets sustainably separate mixtures of rare...
on October 24, 2019 at 8:17 am
A new study describes a novel approach for purifying rare earth metals, crucial components of technology that require environmentally-damaging mining procedures. By relying on the metal's magnetic fields during the crystallization process, researchers were able to efficiently and selectively separate mixtures of rare earth metals.
First identification of a heavy element born from...
on October 23, 2019 at 6:00 pm
For the first time, a freshly made heavy element, strontium, has been detected in space, in the aftermath of a merger of two neutron stars. This finding was observed by ESO's X-shooter spectrograph on the Very Large Telescope (VLT) and is published today in Nature. The detection confirms that the heavier elements in the Universe can form in neutron star mergers, providing a missing piece of the puzzle of chemical element formation.
Deuteron-like heavy dibaryons—a step towards...
on October 22, 2019 at 3:14 pm
Have you ever wondered how the Sun creates the energy that we get from it every day and how the other elements beside hydrogen have formed in our universe? Perhaps you know that this is due to fusion reactions where four nuclei of hydrogen join together to produce a helium nucleus. Such nucleosynthesis processes are possible solely due to the existence, in the first place, of stable deuterons, which are made up of a proton and a neutron. Probing deeper, one finds that a deuteron consists of six […]
Chains of atoms move at lightning speed inside...
on October 15, 2019 at 2:21 pm
A phenomenon that has previously been seen when researchers simulate the properties of planet cores at extreme pressures has now also been observed in pure titanium at atmospheric pressure. Chains of atoms dash around at lightning speeds inside the solid material.