Showing posts with the label physics


this shows that a group of different velocities and phase velocity moving in different direction

Physical Chemistry

Physical Chemistry Gold has been treasured throughout history partly because of its great chemical stability. Resistant to attack by oxygen, which rusts or tarnishes other metals, gold remains bright and beautiful under ordinary environmental conditions for centuries. Gold, however, does oxidize, forming Au2O3, when exposed to environments containing a highly reactive form of oxygen— e.g., atomic oxygen or ozone. Hans-Gerd Boyen of the University of Ulm, Ger., led a German-Swiss team that announced the discovery of a more oxidation-resistant form of gold. The material, called Au55, consists of gold nanoparticles; each nanoparticle is a tiny cluster comprising exactly 55 gold atoms and measuring about 1.4 nm (nanometres). Boyen's group reported that Au55 resisted corrosion under conditions that corroded bulk gold and gold nanoparticles consisting of either larger or smaller numbers of atoms. The researchers speculated that the chemical stability is conferred by special properties

Carbon Chemistry

                                     Carbon Chemistry Scientists continued their search for commercial and industrial applications of the tiny elongated molecular structures known as carbon nanotubes. Discovered in 1991, nanotubes consist of carbon atoms bonded together into graphitelike sheets that are rolled into tubes 10,000 times thinner than a human hair. Their potential applications range from tiny wires in a new generation of ultrasmall computer chips to biological probes small enough to be implanted into individual cells. Many of those uses, however, require attaching other molecules to nanotubes to make nanotube derivatives. In general, methods for making small amounts of derivatives for laboratory experimentation have required high temperatures and other extreme conditions that would be too expensive for industrial-scale production. During the year chemists from Rice University, Houston, Texas, and associates from the Russian Academy of Sciences, Moscow, described groun