CHEMISTRY GLOSSARY

isoelectronic    →   izoelektronske čestice

Isoelectronic refers to a group of atoms or ions having the same number of electrons. For example, F^-, Ne, and Na⁺ are isoelectronics.

laser    →   laser

Laser (light amplification by stimulated emission of radiation) is a light amplifier usually used to produce monochromatic coherent radiation in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum.

electric field    →   električno polje

If a small amount of charge experience a force, there is an electric field in the vicinity. Electric field E is defined in terms of electrostatic force F that would be exerted on positive test charge q_p placed in the field:

SI unit for electric field is N C^-1, or V m^-1.

The electric field due to a point charge q at distance r from it given by:

where ε₀ is permittivity constant, and is ε_o=8.85×10^-12 C² N^-1 m^-2.

electrical double layer    →   električni dvosloj

Electrical double layer is the structure of charge accumulation and charge separation that always occurs at the interface when an electrode is immersed into an electrolyte solution. The excess charge on the electrode surface is compensated by an accumulation of excess ions of the opposite charge in the solution. The amount of charge is a function of the electrode potential. This structure behaves essentially as a capacitor. There are several theoretical models that describe the structure of the double layer. The three most commonly used ones are the Helmholtz model, the Gouy-Chapman model, and the Gouy-Chapman-Stern model.

Lewis acid    →   Lewisova kiselina

Lewis acid is an agent capable of accepting a pair of electrons to form a coordinate bond.

Lewis base    →   Lewisova baza

Lewis base is an agent capable of donating a pair of electrons to form a coordinate bond.

Lewis, Gilbert N.    →   Lewis, Gilbert N.

Gilbert Newton Lewis (1875-1946) is an American chemist whose theory of the electron pair fostered understanding of the covalent bond and extended the concept of acids and bases.

ligand field theory    →   teorija ligandnog polja

Ligand field theory is a description of the structure of crystals containing a transition metal ion surrounded by nonmetallic ions (ligands). It is based on the construction of molecular orbitals involving the d-orbitals of the central metal ion and combinations of atomic orbitals of the ligands.

line spectrum    →   linijski spektar

Red-hot gases give line spectrum, i.e. is they emit electromagnetic rays of defined wavelengths. That kind of emission line of spectrum is characteristic of each chemical element.

London’s force    →   Londonova sila

London’s force is an intermolecular attractive force that arises from a cooperative oscillation of electron clouds on a collection of molecules at close range.