Boiling point The temperature at which the liquid—gas phase change occurs. Sublimation The transition of a substance directly from the solid to the gas phase without passing through a liquid phase.
Relative atomic mass The mass of an atom relative to that of carbon This is approximately the sum of the number of protons and neutrons in the nucleus. Where more than one isotope exists, the value given is the abundance weighted average. Isotopes Atoms of the same element with different numbers of neutrons. CAS number The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems.
Murray Robertson is the artist behind the images which make up Visual Elements. This is where the artist explains his interpretation of the element and the science behind the picture. Where the element is most commonly found in nature, and how it is sourced commercially. Atomic radius, non-bonded Half of the distance between two unbonded atoms of the same element when the electrostatic forces are balanced. These values were determined using several different methods.
Covalent radius Half of the distance between two atoms within a single covalent bond. Values are given for typical oxidation number and coordination. Electron affinity The energy released when an electron is added to the neutral atom and a negative ion is formed.
Electronegativity Pauling scale The tendency of an atom to attract electrons towards itself, expressed on a relative scale. First ionisation energy The minimum energy required to remove an electron from a neutral atom in its ground state. The oxidation state of an atom is a measure of the degree of oxidation of an atom.
It is defined as being the charge that an atom would have if all bonds were ionic. Uncombined elements have an oxidation state of 0. The sum of the oxidation states within a compound or ion must equal the overall charge.
Data for this section been provided by the British Geological Survey. An integrated supply risk index from 1 very low risk to 10 very high risk. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores. The percentage of a commodity which is recycled. A higher recycling rate may reduce risk to supply.
The availability of suitable substitutes for a given commodity. The percentage of an element produced in the top producing country. The higher the value, the larger risk there is to supply. The percentage of the world reserves located in the country with the largest reserves.
A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. Specific heat capacity is the amount of energy needed to change the temperature of a kilogram of a substance by 1 K. A measure of the stiffness of a substance.
It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain. A measure of how difficult it is to deform a material. It is given by the ratio of the shear stress to the shear strain. A measure of how difficult it is to compress a substance. It is given by the ratio of the pressure on a body to the fractional decrease in volume. A measure of the propensity of a substance to evaporate.
It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site. Copyright of and ownership in the Images reside with Murray Robertson.
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Discovery date Discovered by Carl Auer von Welsbach Origin of the name The name is derived from the Greek 'neos didymos' meaning new twin. Named from the Greek words neos and didymos , which together mean "new twin. Say what? Neodymium is pronounced as nee-eh-DIM-ee-em. Neodymium was discovered by Carl F. Auer von Welsbach, an Austrian chemist, in Around the same time that was happening, China was investing deeply in its own rare earth metal mining and production and succeeded.
From the late s to , China became the dominant player and it now controls the majority of the market, said Kanko. The risks involved in relying so significantly on a single source for such a valuable commodity were illustrated during a trade dispute between China and Japan in While the price has since come back down, concerns remain. Toyota, for example, recently developed a new neodymium-reduced magnet, citing concerns about neodymium shortages.
Earlier this year, rare earths narrowly avoided being included on a new list of U. These elements are so important, that the U. Neodymium is used in coloring glasses didymium glass able to adsorb the yellow sodium glare of the flame. This kind of glass is used to protect the eyes of welders.
It is also used to tint glass attractive shades of purple. Neodymium is the second most abundant of the rare-earth elements after cerium an is almost as abundant as copper. It is found in minerals that include all lanthanide minerals, such as monazite and bastnasite.
Reserves of neodymium are estimated to be 8 million tonnes, world production of neodymium oxide is about 7. The amount of neodymium in humans is quite small and, although the metal has no biological role, it can be effects on parts of the body: neodymium dust and salts are very irritating to the eyes. Ingested neodymium salts are regarded as only slightly toxic if they are soluble and non toxic if they are insoluble.
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