CHEMISTRY GLOSSARY

close-packed structure    →   gusta slagalina

Close packing is the packing of spheres so as to occupy the minimum amount of space. The name close packed refers to the packing efficiency of 74.05 %. There are two types of close packing: hexagonal and cubic. One layer, with atoms centered on sites labeled a. Two layers, with the atoms of the second layer centered on sites labeled b. The third layer can be placed on the sites labeled c (giving cubic close-packing) or over those marked a (giving hexagonal close-packing).

diazo compounds    →   diazo-spojevi

Diazo compounds are compounds having the divalent diazo group, =N⁺=N^-, attached to a carbon atom. The term includes azo compounds, diazonium compounds, and also such compounds as diazomethane, CH₂=N₂.

dienes    →   dieni

Dienes are unsaturated organic compounds that contain two fixed double bonds between carbon atoms. Dienes in which the two double-bond units are linked by one single bond are termed conjugated.

electromagnetic wave    →   elektromagnetski val

All matter absorbs and emits radiation covering a broad band of frequencies and wavelengths. Thus electromagnetic radiation has the velocity of light (2.998×10⁸ ms^-1) and arises from the vibrating electric charges in atoms and bonds. The range of wavelengths, also known as the electromagnetic spectrum, is shown below:

conformation    →   konformacija

Conformation is one of the very large numbers of possible spatial arrangements of atoms that can be interconverted by rotation about a single bond in a molecule. The conformation of a molecule is not fixed, though one or another shape may be more likely to occur. There are two extreme cases:

Staggered conformation (antiperiplanar) is a conformation about a carbon-carbon single bond in which the atoms on one carbon are as far apart as possible from the atoms on an adjacent carbon.

Eclipsed conformation (syn-periplanar) is a conformation about a carbon-carbon single bond in which the atoms on one carbon are as close as possible to the atoms on an adjacent carbon.

corrosion    →   korozija

Corrosion is a harmful and undesirable construction material consumption by the chemical activity of its surroundings. Corrosion concept refers to metal and nonmetal construction materials, but it is usually used for metals, Corrosion of metal, according to the mechanism process, is divided into chemical (corrosion in nonelectrolytes) and electrochemical (corrosion in electrolytes).

Chemical corrosion appears by direct action of molecule of some element or compound on metal, thus directly creating corrosion products.

Electrochemical corrosion of metals occurs in electrolytes, so reduction of metal atom into free cation appears which by secondary processes gives molecules of compound which are considered a corrosion product.

covalent bond    →   kovalentna veza

Covalent bond is a chemical bond between two atoms whose stability results from the sharing of two electrons, one from each atom (H· + ·H = H:H or H-H).

electron volt    →   elektronvolt

Electron volt (eV) is a non-SI unit of energy used in atomic and nuclear physics, equal to approximately 1.602 177×10^-19 J. The electron volt is defined as the kinetic energy acquired by an electron upon acceleration through a potential difference of 1 V.

element    →   element

Element is a substance that cannot be decomposed into simpler substances. In an element, all the atoms have the same number of protons or electrons, although the number of neutrons my vary.

elementary reaction    →   elementarna reakcija

Elementary reaction is a reaction that occurs in a single step. Equations for elementary reactions show the actual molecules, atoms, and ions that react on a molecular level.