reduced mass
51spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …
52Rocket — This article is about vehicles powered by rocket engines. For other uses, see Rocket (disambiguation). A Soyuz U, at Baikonur Site 1/5 A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engi …
53Bohr radius — Unit of length name=Bohr radius m=0.000000000052917720859 accuracy=6In the Bohr model of the structure of an atom, put forward by Niels Bohr in 1913, electrons orbit a central nucleus. The model says that the electrons orbit only at certain… …
54Kinetic isotope effect — The kinetic isotope effect (KIE) is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction. It is also called isotope fractionation, although this term is somewhat broader in meaning. A KIE involving… …
55Voided biaxial slab — Voided biaxial slabs are reinforced concrete slabs in which voids reduce the amount of concrete.While concrete have been used for thousands of years, the use of reinforced concrete is a relative recent invention, usually attributed to Joseph… …
56Positronium — (Ps) is a system consisting of an electron and its anti particle, a positron, bound together into an exotic atom . Being unstable, the two particles annihilate each other to produce two gamma ray photons after an average lifetime of 125 ps or… …
57Classical central-force problem — In classical mechanics, the central force problem is to determine the motion of a particle under the influence of a single central force. A central force is a force that points from the particle directly towards (or directly away from) a fixed… …
58Shotgun — For other uses, see Shotgun (disambiguation). A pump action Remington 870, two semi automatic …
59Molecular vibration — A molecular vibration occurs when atoms in a molecule are in periodic motion while the molecule as a whole has constant translational and rotational motion. The frequency of the periodic motion is known as a vibration frequency, and the typical… …
60Heavy Rydberg system — A heavy Rydberg system consists of a weakly bound positive and negative ion orbiting their common centre of mass. Such systems share many properties with the conventional Rydberg atom and consequently are sometimes referred to as heavy Rydberg… …
