CHEMISTRY GLOSSARY

bathymetry    →   batimetrija

Bathymetry (from the Greek word bathus, deep) is the science of measuring the depths of the oceans, seas, lakes, etc. or the topographic maps of the sea floor that result from such measurements. Bathymetric charts are designed to present accurate, measurable description and visual presentation of the submerged terrain.

blanching    →   blanširanje

1. Blanching is a heat treatment of foodstuffs to partially or completely inactivate the naturally occurring enzymes prior to freezing.

2. Blanching is a washing process for coins cleaning. The black surface layer of cupric oxide is removing by dipping the coins in hot dilute sulphuric acid (w(H₂SO₄) = 10 %).

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.

argon    →   argon

Argon was discovered by Lord Raleigh and Sir William Ramsay (Scotland) in 1894. The origin of the name comes from the Greek word argos meaning inactive. It is colourless and odourless noble gas. Chemically inert. It is the third most abundant element in the earth’s atmosphere and makes up about 1 %. Argon is continuously released into the air by decay of radioactive potassium-40. Pure form is obtained from fractional distillation of liquid air. Used in lighting products. It is often used in filling incandescent light bulbs. Some is mixed with krypton in fluorescent lamps. Crystals in the semiconductor industry are grown in argon atmospheres.

Beer’s law    →   Beerov zakon

Beer’s law (or Beer-Lambert law) is the functional relationship between the quantity measured in an absorption method (A) and the quantity sought, the analyte concentration (c). As a consequence of interactions between the photons and absorbing particles, the power of the beam is attenuated from P_o to P. Beer’s law can be written

where A is the absorbance at a given wavelength of light, ε is the molar absorbtivity or extinction coefficient (L mol^-1 cm^-1), unique to each molecule and varying with wavelength, b is the length of light path through the sample (cm), and c is the concentration of the compound in solution (mol L^-1).

carotenoids    →   karotenoidi

Carotenoids are a group of natural pigments in plants responsible for yellow and orange colours, meltable in fats.

detergent    →   deterdžent

Detergent is a substance added to water to improve its cleaning properties. Although water is a powerful solvent for many compounds, it will not dissolve grease and natural oils. Detergents are compounds that cause such nonpolar substances to go into solution in water. Soap is the original example, owing its action to the presence of ions formed from long-chain fatty acids ion (e.g. stearat ion, CH₃(CH₂)₁₆COO^-).

elastomer    →   elastomer

Elastomer is a natural or synthetic rubber or rubberoid material, which has the ability to undergo deformation under the influence of a force and regain its original shape once the force has been removed.

environment protection    →   zaštita okoliša

From Environment protection law of the Republic of Croatia: By protection of the environment, the following is ensured: complete preservation of environment quality, natural community preservation, rational usage of natural resources and energy in the most favourable way concerning the environment as a basic condition of healthy and sustainable development.

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)