All Elements and the periodic table articles – Page 12

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On This Day - Apr 13 : Tellurium discovered

This semi-metal was discovered by Austro-Hungarian mineralogist Baron Franz Muller von Reichenstein. It is obtained as a grey powder and its compounds are not only poisonous, but even the tiniest amounts can lead to unpleasant body odours!
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On This Day – Jul 12 : Discovery of xenon

The British chemists used a powerful machine that cooled and liquefied air to obtain krypton (Kr). They then repeatedly distilled the krypton until an even denser substance separated out, which they named xenon (Xe).
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On This Day - Dec 12 : Compounds of californium

By treating californium (Cf) with steam and hydrochloric acid, Burris Cunningham and James Wallman of the Lawrence Radiation Laboratory of the University of California had created californium trichloride, oxychloride, and oxide.
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On This Day - Mar 10 : Charles Hatchett died

He first discovered an element that he named columbium but was later rediscovered by German chemist Heinrich Rose and was named niobium (Nb).
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On This Day - May 10 : Caesium was discovered

Caesium (Cs) was discovered in spring waters by Robert Bunsen and Gustav Kirchoff. Although they were the first to identify the new element, Carl Setterberg was the first to isolate the metal itself.
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On This Day – Jul 10 : Onnes made liquid helium

Helium has the lowest boiling point of the elements at -269 °C, or 4 Kelvin on the absolute temperature scale. It must be cooled down to between 1 and 4 K to exist as a liquid. For this work, Onnes won the Nobel Prize in Physics in 1913.
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On This Day - Mar 09 : Stanley Thompson was born

He led the Berkeley team, which included Glenn Seaborg, in the discovery of seven new actinide elements: americium (Am), berkelium (Bk), curium (Cm) californium (Cf), einsteinium (Es), fermium (Fm) and mendelevium (Md).
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On This Day - Nov 09 : Darmstadtium was created

It was made by a nuclear fusion reaction involving an isotope of lead (Pb) and an isotope of nickel (Ni). Darmstadtium decays within a thousandth of a second, and therefore an observable amount has never been isolated.
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On This Day - Jun 08 : Neptunium discovered

Neptunium (Np) was synthesised by Edwin McMillan and Philip H. Abelson, who bombarded uranium (U) with neutrons to cause nuclear fission. Neptunium is rare in nature and is only made artificially from spent uranium rods in nuclear reactors.
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On This Day - Dec 08 : Roentgenium discovered

The name roentgenium (Rg) was proposed in honour of the German physicist Wilhelm Conrad Röntgen, and was accepted as a permanent name on November 1, 2004.
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On This Day - Mar 06 : Mendeleev's Periodic Table

Although this was not the first attempt to systematically order the chemical elements, Mendeleev’s table was unique, allowing him to predict undiscovered elements as well as revealing inaccuracies in some of the measured atomic weights.
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On This Day – Jul 05 : George de Hevesy died

He was awarded the 1943 Nobel Prize in Chemistry for his work on radioisotopes and their use as tracers in studying the chemical processes within living systems. He also discovered the element hafnium (Hf) with Dick Coster in 1923.
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On This Day - Mar 03 : Joseph Wharton was born

He improved the process of refining nickel (Ni) and his company made the first pure nickel metal. Wharton was the driving force in establishing the zinc (Zn) and nickel metal industries in the United States.
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On This Day – Jul 03 : Discovery of bromine

The French chemist was an unknown young laboratory assistant when he discovered the element in seawater, which is a liquid at room temperature. This was independent to Carl Jacob Löwig’s preparation of bromine one year earlier. The word bromine comes from the Greek word bromos, meaning “stench”.
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On This Day – Aug 03 : Platinum catalysis

He realised that a platinum (Pt) sponge could cause the ignition of hydrogen (H) at room temperature by lowering the activation energy. This effect was the precursor to the theory of catalysis, and in 1835 the term “catalyst” was coined by Swedish chemist Jacob Berzelius.
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On This Day - Oct 02 : First atomic clock

Atomic clocks keep time using the microwave signal that is emitted when electrons in atoms change energy levels. This early clock, the Atomicron, used the constant frequency from the oscillations of the caesium (Cs) atom at 9,192,631,830 MHz.
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On This Day - Dec 01 : Martin Klaproth was born

In 1789 he discovered uranium (U), which was named after the planet Uranus. This planet was actually discovered eight years earlier by another German scientist, William Hershel.
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On This Day - Jan 24 : Morris Travers was born

He worked with Scottish chemist William Ramsay to discover the noble gases krypton (Kr), xenon (Xe) and neon (Ne). He also played a pivotal role in setting up the Indian Institute of Science in Bangalore.
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On This Day - Jan 21 : Magnesium produced

Magnesium (Mg) was first extracted from seawater through an electrolytic process. Is the lightest of all structural elements – one-third less dense than aluminium – and is used in flares, pyrotechnics, incendiary bombs, aeroplane and missile construction.
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On This Day - Jan 20 : de Chancourtois was born

He was the first person to organise elements by atomic weights, by plotting a graph of the elements around a cylinder with a circumference of 16 units corresponding to the weight of oxygen (O). Elements that appeared above and below each other shared similar periodic properties.