Chemistry Nexus
by WebElements: the periodic table on the web
Royal Society Digital Journal Archive Free from 23 Nov to 28 Feb 2010
Royal Society Digital Journal Archive Free from 23 Nov to 28 Feb 2010.
The year “2010 is going to be a very special year at the Royal Society. As the worlds oldest science academy, we are looking forward to celebrating our 350th anniversary and to mark this special occasion we are making our digital archive containing more than 65,000 articles free to access.
WebElements November 23rd, 2010
Posted In: Chemistry, History of chemistry
Synthesis of a new element with atomic number Z=117
International team discovers element 117
A new chemical element has been added to the Periodic Table: A paper on the discovery of element 117 has been accepted for publication (5 April 2010) in Physical Review Letters.1
Abstract
The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk.
WebElements April 12th, 2010
Posted In: Chemistry, Group 17 elements, Nuclear chemistry, p-Block, Radioactive elements
Ground State Electron Configuration of Rutherfordium: Role of Dynamic Correlation
The low-lying electronic states of Rf+ and Rf are investigated by the relativistic coupled cluster method based on the Dirac-Coulomb-Breit Hamiltonian. A large basis set (34s24p19d13f8g5h4i) of Gaussian-type orbitals is used. The external 36 electrons are correlated. In contrast with recent multiconfiguration Dirac-Fock (MCDF) results, the 7s26d2 3F2 state is found to be the ground state of the atom, lying about 0.30 eV below the 7s27p6d 3D2 state (the MCDF ground state).
WebElements December 24th, 2009
Posted In: Chemistry
X-ray study of the alkali metals at low temperatures
Cold working of sodium metal converts body centred sodium metal to a mixture of a hexagonal form and body centred sodium at 5 K. The hexagonal from converts back to the body-centred form at 100-100 K.Cold working of lithium metal converts body centred lithium metal to a mixture of a hexagonal form and body centred lithium at 78 K.
Potassium, rubidium, and caesium retain their body centred structure after cooling.
WebElements December 24th, 2009
Posted In: Chemistry, Crystallography, Group 1 elements
Crystallographic Data 186. Lithium
Lithium at room temperature is body-centered cubic with 2 atoms per unit cell. The lattice constant for lithium metal is 3.51004 ± 0.00041 Å at 25°C. The theoretical density is 533 kg m–3 and the Li—Li bond distance for coordination number 8 is 3.0398 Å.1
SMILES: [Li]InChI: InChI=1/Li
References
WebElements December 24th, 2009
Posted In: Chemistry, Crystallography, Group 1 elements
Tags: Lithium
Crystallographic data for uranium mononitride
Uranium nitride, UN, is available through the direct reaction of uranium metal and nitrogen. The crystal structure is the NaCl type.
Abstract1
Crystal structure of uranium nitride, UN. The structure is face-centered cubic with a lattice constant of 4889 ± 0.001 Å at 26°C and sodium chloride type. The theoretical density is 14315 kg m–3, and the U—N bond distance for coordination number 6 is 2.4449 Å.
WebElements December 24th, 2009
Posted In: Chemistry, Crystallography
Helium supersolids?
In a letter to Nature E. Kim and M. H. W. Chan (Pennsylvania State University, USA) note that when liquid 4He is cooled below 2.176 K, it undergoes a phase transition and becomes a superfluid with zero viscosity. They claim that in addition to superflow in the liquid phase, superflow can also occur under some conditions in the solid phase of one of the helium isotopes (4He), and present results to back this up.
WebElements December 19th, 2009
Posted In: Chemistry
Approaches to element 120 (unbinilium)
Attempts have been made at GSI to make element 120 (unbinilium). Several new elements have been made at GSI in the last few years. However after 120 days no decay chain of element 120 was found. With the total number of 2.6 × 1019 projectiles which impinged upon the target, it deduced that the stability in the region around Z=120, N=184 is not exceptionally high with respect to the neighbouring regions.
WebElements December 17th, 2009
Posted In: Chemistry
Energy dependence of 209-Bi fragmentation in relativistic nuclear collisions
The results of cross-section measurements for the reactions 209Bi(12C,X)Au, E=4.8 and 25.2 GeV and 209Bi(20Ne,X)Au, E=8.0 GeV are reported. The observed yields of the gold isotopes show a similar dependence on mass number for each reaction, differing slightly in the position of the centroid of the distribution. As the projectile energy increases, the inferred excitation energy of the primary residues remains the same or decreases slightly.
WebElements December 17th, 2009
Posted In: Chemistry, Nuclear chemistry
Tags: Bismuth
Die Kristallstrukturen von ScCl3, TiCl3 und VCl3
ScCl3, TiCl3 und VCl3 kristallisieren hexagonal-rhomboedrisch in dem gleichen Gitter wie FeCl3 (DO5-Typ).
The trichlorides ScCl3, TiCl3 and VCl3 crystallise hexagonal-rhombohedral in the same system as FeCl3 (DO5-type )1
References
WebElements December 16th, 2009
Posted In: Chemistry