It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is…

Nanotechnology is viewed by those in favor of its development in two different ways, and the divide is not recent. This article describes the origins of the differing visions of nanotechnology and examines their broader impacts. The typical history of the field tells nothing about these differing visions, which perhaps misleads. At least two…

Hydrogen activation on the (100) surface of MoS[2] structures was investigated by means of density functional theory calculations. Linear and quadratic synchronous transit methods with a conjugate gradient refinement of the saddle point were used to localize transition states. The calculations include heterolytic and homolytic dissociation of…

In the first phase of the research project Nanotechnologies for Tomorrow's Society (www.nanosoc.be), the research consortium explored a variety of futuristic visions or technoscientific imaginaries. This exploration took the form of a Policy Delphi, adapted to the particular objective of jointly constructing nano-imaginaries, taking participants'…

Discusses three broad classes of magnetic behavior: diamagnetic, paramagnetic, and ferromagnetic. Presents a simple lecture demonstration using an overhead projector to synthesize triiron tetraoxide and to show its interaction with a magnetic field and comparing it to a paramagnetic material. (MVL)

Uses simple pulse NMR experiments to discuss Fourier transforms. Studies the generation of spin echoes used in the imaging procedure. Shows that pulse NMR experiments give signals that are additions of sinusoids of differing amplitudes, frequencies, and phases. (MVL)

Presents the mechanistic ideas underlying reactions between nucleophiles and carbonyl compounds as well as some popular misconceptions. Relates reactions of carboxylic acid derivatives to those of aldehydes and ketones. Discusses leaving group ability and the ability of carbonyl oxygen to accept a negative charge. (Author/MVL)

Understanding the basic principles of structural biology is becoming a major subject of study in most undergraduate level programs in biology. In the genomic and proteomic age, it is becoming indispensable for biology students to master concepts related to the sequence and structure of proteins in order to develop skills that may be useful in a…