CHEMISTRY GLOSSARY

nascent state    →   nascentno stanje

Nascent state is an especially active state of an element in a moment when it is released from a compound during chemical reaction, e.g. nascent hydrogen.

neon    →   neon

Neon was discovered by Sir William Ramsay and Morris W. Travers (England) in 1898. The origin of the name comes from the Greek word neon meaning new. It is colourless, odourless inert gas. Non-reactive even with fluorine. Fourth most abundant element in the universe. Neon is obtained by liquefaction of air and separated from the other gases by fractional distillation. Primarily for lighting.

enthalpy    →   entalpija

Enthalpy (H) is a thermodynamic property of a system defined by

where U is the internal energy of the system, p its pressure, and V its volume. J.W. Gibbs put the concept of an ensemble forward in 1902. In a chemical reaction carried out in the atmosphere the pressure remains constant and the enthalpy of reaction (ΔH), is equal to

For an exothermic reaction ΔH is taken to be negative.

erbium    →   erbij

Erbium was discovered by Carl Gustaf Mosander (Sweden) in 1843. Named after Ytterby, a village in Sweden. It is soft, malleable, silvery metal. Reacts slowly with water. Dissolves in acids. Metal ignites and burns readily. Erbium is found with other heavier rare earths in xenotime and euxenite. Erbium oxide is used in ceramics to obtain a pink glaze. Also a few uses in the nuclear industry and as an alloying agent for other exotic metals.

Erlenmeyer flask    →   Erlenmeyerova tikvica

Erlenmeyer flask is a glass container which has a narrow, cylindrical mouth and a cone-shaped main body that ends in a wide, flat bottom. It was named after its inventor, a German chemist Richard Erlenmeyer (1825-1909). Erlenmeyer flasks are most often used in titrations to hold the liquid that is being titrated.

explosive    →   eksploziv

Explosive is a compound or mixture that, when ignited or detonated, undergoes rapid violent chemical reaction that produces large amount of gas and heat, accompanied by light, sound and a high pressure shock wave.

oxidation    →   oksidacija

The term oxidation originally meant a reaction in which oxygen combines chemically with another substance. More generally, oxidation is a part of a chemical reaction in which a reactant loses electrons (increases oxidation number). Simultaneous reduction of a different reactant must occur (redox reaction).

permeability    →   permeabilnost

Permeability (Latin permeare, to pass through) is a passage or diffusion of a gas, vapour, liquid, or solid through a material without physically or chemically affecting it.

pesticide    →   pesticid

Pesticides are chemical means against pests in agriculture. They are used for annihilation of weed (herbicides), insects (insecticides) and funguses (fungicides). They have a toxic effect on man and are the most frequent cause of food pollution.

polymorphic transition    →   polimorfni prijelaz

Polymorphic transition is a reversible transition of a solid crystalline phase at a certain temperature and pressure to another phase of the same chemical composition with a different crystal structure. For examples, the transitions of quartz (SiO₂) at 1 143 K to tridymite, and at 1 743 K to cristobalite.