CHEMISTRY GLOSSARY

mixture    →   smjesa

Mixture is a heterogeneous association of substances where various individual substances retain their identities and can usually be separated by mechanical means. Includes solutions or compounds but does not include alloys or amalgams.

foam    →   pjena

Foams are dispersions of gases in liquids or solids. The gas globule may be of any size, from colloidal to macroscopic, as in soap bubbles. Bakers’ bread and sponge rubber are examples of solid foams. Typical liquid foams are those used in fire-fighting, shaving creams, etc. Foams made by mechanical incorporation of air are widely used in the food industry (e.g. whipped cream, egg white, ice cream, etc.). Foams can be stabilized by surfactants.

inert electrode    →   inertna elektroda

Inert electrode is an electrode that serves only as a source or sink for electrons without playing a chemical role in the electrode reaction. Precious metals, mercury, and carbon are typically used as inert electrodes. The inert nature of the electrode can sometimes be questioned. While the electrode may not take part in the reaction as a reactant or product, it still can act as an electrocatalyst.

magnetic permeability    →   magnetska permeabilnost

Magnetic permeability (μ), also called permeability, is a constant of proportionality that exists between magnetic induction and magnetic field intensity. This constant is equal to approximately μ_o = 1.257×10^-6 H/m in a vacuum.

Magnetic permeability is often expressed in relative, rather than in absolute, terms. If μ represents the permeability of the substance in question, then the relative permeability, μ_r, is given by:

neutral substance    →   neutralna tvar

Neutral substance is a substance that shows no acid or base properties, has an equal number of hydrogen and hydroxyl ions and does not change the colour of litmus-paper.

strength    →   čvrstoća

Strength is a mechanical characteristic of a solid body, that gives the resistance to cutting. The solid body comprises from one to more crystals.

piezoelectric effect    →   piezoelektrični efekt

Piezoelectric effect is voltage produced between surfaces of a solid dielectric (nonconducting substance) when a mechanical stress is applied to it. A small current may be produced as well. The effect, discovered by the French physicist Pierre Curie (1859-1906) in 1883, is exhibited by certain crystals, e.g., quartz and Rochelle salt, and ceramic materials. When a voltage is applied across certain surfaces of a solid that exhibits the piezoelectric effect, the solid undergoes a mechanical distortion. Piezoelectric materials are used in transducers, e.g., phonograph cartridges, microphones, and strain gauges, which produce an electrical output from a mechanical input, and in earphones and ultrasonic radiators, which produce a mechanical output from an electrical input.

polonium    →   polonij

Polonium was discovered by Marie Curie (Poland) in 1898. Named for Poland, native country of Marie Curie. It is silvery-grey, extremely rare, radioactive metal. Soluble in dilute acids. Highly toxic. Severe radiotoxicity. Carcinogen. Polonium occurs in pitchblende. Produced by bombarding bismuth with neutrons. Used in industrial equipment that eliminates static electricity caused by such processes as rolling paper, wire and sheet metal.

precision balance    →   tehnička vaga

Precision balances typically display results from three to one decimal places (0.001 g up to 0.1 g). The readability precision balances are reduced when compared to analytical balances but, precision balances accommodate higher capacities (up to several kilograms). In its traditional form, it consists of a pivoted horizontal lever of equal length arms, called the beam, with a weighing pan, also called scale, suspended from each arm.

In electronic top pan, or toploader balances, mass is determined not by mechanical deflection but by electronically controlled compensation of an electric force. The signal generated enables the mass to be read from a digital display. The mass of the empty container can be stored in the balance’s computer memory and automatically deducted from the mass of the container plus its contents.

volumetry    →   volumetrija

Volumetry consists of adding an equivalent amount of a reagent of exactly known concentration to the analyte. From stechiometrical proportion and added volume of reagent the quantity of matter in question can be calculated.