CHEMISTRY GLOSSARY

control rod    →   kontrolna šipka

Control rods are rods in a nuclear reactor composed of substances that absorb neutrons (cadmium, hafnium, boron, etc.). These rods regulate the power level of the reactor.

convection    →   konvekcija

Convection is the process by which heat is transferred from one part of a fluid to another by movement of the fluid itself. There are two methods by which this can be carried out.

Natural convection, in which movement occurs as a result of gravity. Heat transferred through a fluid medium, such as air or water, by currents that result from the rising of less dense, warm fluid and the sinking of heavier, cooler fluid.

Forced convection is where hot fluid is transferred from one region to another by a mechanical means (fans or pumps).

coulometer    →   kulometar

Coulometer is a type of electrolysis cell which is used for measuring the quantity of one element released during electrolysis.

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).

cracking    →   krekiranje

Cracking is the process whereby heavy molecules of petroleum or crude oil are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process).

critical point    →   kritična točka

In general, critical point is the point on the phase diagram of a two-phase system at which the two coexisting phases have identical properties and therefore represent a single phase. At the liquid-gas critical point of a pure substance, the distinction between liquid and gas vanishes, and the vapour pressure curve ends. The coordinates of this point are called the critical temperature and critical pressure. Above the critical temperature it is not possible to liquefy the substance.

critical pressure    →   kritični tlak

Critical pressure is the pressure of a fluid in its critical point; i.e. when it is at its critical temperature and critical volume.

critical temperature    →   kritična temperatura

Critical temperature is the temperature of the liquid-vapour critical point, that is, the temperature above which a gas cannot be liquefied by an increase of pressure.

crucible    →   lončić za žarenje

Crucible is used for heating small amounts of solid in an oven to very high temperatures. Crucibles are usually made out of porcelain, platinum, nickel or iron.

crude oil    →   sirova nafta

Crude oil (petroleum) is a fossil fuel formed from plant and animal remains many million of years ago. It is occasionally found in springs or pools but is usually drilled from wells beneath the earth’s surface. Crude oil is a mixture of hydrocarbons with small quantities of other chemicals such as sulphur, nitrogen and oxygen. Crude is the raw material which is refined into petrol, heating oil, jet fuel, propane, petrochemicals, and other products.