Chemistry Nexus

by WebElements: the periodic table on the web

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.

Read more…

April 12th, 2010

Posted In: Chemistry, Group 17 elements, Nuclear chemistry, p-Block, Radioactive elements

Leave a Comment

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).

Read more…

December 24th, 2009

Posted In: Chemistry

Leave a Comment

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.

Read more…

December 24th, 2009

Posted In: Chemistry, Crystallography, Group 1 elements

Tags: , , , ,

Leave a Comment

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

1. Nadler, M. R., and C. P. Kempier. 1959. “Crystallographic Data 186.
Read more…

December 24th, 2009

Posted In: Chemistry, Crystallography, Group 1 elements

Tags:

Leave a Comment

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.

Read more…

December 24th, 2009

Posted In: Chemistry, Crystallography

Leave a Comment

Helium (He)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.

Read more…

December 19th, 2009

Posted In: Chemistry

Leave a Comment

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.

Read more…

December 17th, 2009

Posted In: Chemistry

Leave a Comment

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.

Read more…

December 17th, 2009

Posted In: Chemistry, Nuclear chemistry

Tags:

Leave a Comment

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

1. Klemm, Wilhelm, and Ehrhard Krose. “Die Kristallstrukturen von ScCl3, TiCl3 und VCl3“, Z.
Read more…

December 16th, 2009

Posted In: Chemistry

Leave a Comment

The positions of the elements La, Ac, Lu, and Lr in the WebElements periodic table is justified eloquently in the article by William B. Jensen.1

Abstract:1 The debate as to whether lanthanum and actinium or lutetium and lawrencium should be placed in group IIIB of the periodic table along with scandium and yttrium has along but poorly publicized history.

Read more…

December 16th, 2009

Posted In: Chemistry

« Previous PageNext Page »