CHEMISTRY GLOSSARY

ABS plastic    →   ABS

ABS plastic is any of a class of plastics or plastics based on acrylonitrile-butadiene-styrene copolymers.

Acheson process    →   Achesonov proces

Acheson process is an industrial process to synthesize graphite and silicon carbide (carborundum), named after its inventor the American chemist Edward Goodrich Acheson (1856-1931). In this process, a solid-state reaction between pure silica sand (SiO₂) and petroleum coke (C) at very high temperature (more than 2500 °C) leads to the formation of silicon carbide under the general reaction:

While studying the effects of high temperature on carborundum, Acheson had found that silicon vaporizes at about 4150 °C, leaving behind graphitic carbon.

adiabatic process    →   adijabatski proces

Adiabatic process is a thermodynamic process in which no heat enters or leaves the system. In general, an adiabatic change involves a fall or rise in temperature of the system.

alpha particle    →   alfa-čestica

Alpha particle is a helium nucleus emitted spontaneously from radioactive elements, both natural and manufactured. Its energy is in range 4-8 MeV and is dissipated in a very short path, i.e. a few centimetres of air or less than 0.005 mm of aluminium. As helium nucleus consists of two protons and two neutrons bound together as a stable entity the loss of an alpha particle involves a decrease in nucleon number of 4 and decrease of 2 in the atomic number, e.g.

A stream of alpha particles is known as an alpha ray or alpha-radiation.

atmospheric pressure    →   atmosferski tlak

Atmospheric pressure is the pressure exerted by weight of the air above it at any point on the earth’s surface. At sea level the atmosphere will support a column of mercury about 760 mm high. This decreases with increasing altitude. The standard value for the atmospheric pressure at sea level in SI units is 101 325 Pa.

basic Bessemer process    →   bazni Bessemerov proces

Basic Bessemer process is the process of steelmaking in a way that steel, melted iron and limestone are put in the blast-furnace after which the metal oxygen is released in gushes in order to oxidise the impurities.

boiling point    →   vrelište

Boiling point is the temperature at which the vapour pressure of a liquid is equal to the external pressure on the liquid. The standard boiling point is the temperature at which the vapour pressure of a liquid equals standard pressure (101 325 Pa).

boiling point elevation    →   povišenje vrelišta

Boiling point elevation is an elevation of the boiling point of a solvent is observed when substances are dissolved in it. The amount by which the boiling point is elevated is proportional to the number of molecules of solute and independent of their nature.

beta particle    →   beta-čestica

Beta particle is a charged particle emitted from a radioactive atomic nucleus either natural or manufactured. The energies of beta particles range from 0 MeV to 4 MeV. They carry a single charge; if this is negative, the particle is identical with an electron; if positive, it is a positron.

An unstable atomic nucleus changes into a nucleus of the same mass number but different proton number with the emission of an electron and an antineutrino (or a positron and a neutrino)

chemical property    →   kemijsko svojstvo

Chemical property is a property observed when a substance undergoes a transformation into one or more new substances. Measurement of a chemical property involves a chemical change. For example, determining the flammability of petrol involves burning it, producing carbon dioxide and water.