CHEMISTRY GLOSSARY

peptide    →   peptid

Peptides are amides derived from two or more amino acids (the same or different) linked by peptide bonds. These bonds are formed by the reaction between adjacent carboxyl (-COOH) and amino (-NH₂) groups with the elimination of water.

peptide bond    →   peptidna veza

Peptide bond emerges when two amino acid join in a way that the carbon atom from one connects with the nitrogen atom from the other (creating a C-N bond).

water purification    →   pročišćavanje vode

Water purification is a procedure of harmful substances removal in order to obtain pure drinking-water.

water softening    →   omekšavanje vode

Water softening is a process in which calcium and magnesium ions are removed from water. It is usually done by ion exchanger which exchanges removed ions with sodium ones.

welding    →   varenje

Welding is a process of joining of two metal surfaces that have been heated, melted, and fused together.

wrinkled filter paper    →   nabrani filtar-papir

Wrinkled filter paper is a filter made of wrinkled filter paper, by which, due to enlarged surface, fast filtering is achieved.

Petri dish    →   Petrijeva zdjelica

Petri dish is a shallow glass or plastic flat bottomed dish with a lid. Used primarily in laboratories for the culture of bacteria and other microorganisms on specially prepared media. It was named after the German bacteriologist Julius Richard Petri (1852-1921) who invented it in 1877.

petroleum    →   nafta

Petroleum (crude oil) is a dark viscous liquid usually found under Earth’s surface or sea bottom. It is a very complex mixture of different compounds, mostly of hydrocarbonates of alkane, cycloalkane and aromatic sort whose composition is variable from oil field to oil field.

pH    →   pH

pH is a convenient measure of the acid-base character of a solution, usually defined by

where c(H⁺) is the concentration of hydrogen ions in moles per litre. The more precise definition is in terms of activity rather than concentration.

A solution of pH 0 to 7 is acid, pH of 7 is neutral, pH over 7 to 14 is alkaline.

phosphorescence    →   fosforescencija

Phosphorescence is emission of light from a substance exposed to radiation and persisting as an afterglow after the exciting energy has been removed. Unlike fluorescence, in which the absorbed energy is spontaneously emitted about 10^-8 second after excitation, phosphorescence requires additional excitation to produce radiation and may last from about mili second to days or years, depending on the circumstances.