CHEMISTRY GLOSSARY

base-centered orthorhombic lattice    →   bazno centrirana ortorompska rešetka

Base-centered or side-centered or end-centered monoclinic lattice (orthorhombic-C), like all lattices, has lattice points at the eight corners of the unit cell plus additional points at the centers of two parallel sides of the unit cell. It has unit cell vectors a≠b≠c and interaxial angles α=β=γ=90°.

electroorganic reaction    →   elektroorganske reakcije

Electroorganic reaction is an organic reaction produced in an electrolytic cell. Electroorganic reactions are used to synthesise compounds that are difficult to produce by conventional techniques. An example of an electroorganic reaction is Kolbe’s method of synthesising alkanes.

Faraday cage    →   Faradayev kavez

Faraday cage is a container giving protection from electrical fields: an assembly of conducting material, for example, metal mesh or grid, placed around electrical equipment to protect it from external electrical fields. Faraday cages are named after the English scientist Michael Faraday (1791-1867).

galvanostat    →   galvanostat

Galvanostat is an electronic instrument that controls the current through an electrochemical cell at a preset value, as long as the needed cell voltage and current do not exceed the compliance limits of the galvanostat.

impedance    →   impedancija

Impedance is the analogue of the resistance or resistivity when applied to alternating current. That is, it is a measure of a material’s inability to carry the electrical current. In many materials the impedance varies as the frequency of the applied electrical potential changes, due to the properties of the conducting liquid or solid. In electrochemistry, the impedance of the electrodes is also frequency dependent.

body-centered cubic lattice    →   prostorno centrirana kubična rešetka

Body-centered cubic lattice (bcc or cubic-I), like all lattices, has lattice points at the eight corners of the unit cell plus an additional points at the center of the cell. It has unit cell vectors a = b = c and interaxial angles α=β=γ=90°.

The simplest crystal structures are those in which there is only a single atom at each lattice point. In the bcc structures the spheres fill 68 % of the volume. The number of atoms in a unit cell is two (8 × 1/8 + 1 = 2). There are 23 metals that have the bcc lattice.

body-centered orthorhombic lattice    →   prostorno centrirana ortorompska rešetka

Body-centered orthorhombic lattice (orthorhombic-I), like all lattices, has lattice points at the eight corners of the unit cell plus an additional points at the center of the cell. It has unit cell vectors a≠b≠c and interaxial angles α=β=γ=90°.

lattice constants    →   konstante kristalne rešetke

Lattice constants are parameters specifying the dimensions of a unit cell in a crystal lattice, specifically the lengths of the cell edges and the angles between them.

body-centered tetragonal lattice    →   prostorno centrirana tetragonska rešetka

Body-centered tetragonal lattice (tetragonal-I), like all lattices, has lattice points at the eight corners of the unit cell plus an additional points at the center of the cell. It has unit cell vectors a=b≠c and interaxial angles α=β=γ=90°.

Bragg angle    →   Braggov kut

Bragg angle (Θ) is the angle between an incident X-ray beam and a set of crystal planes for which the secondary radiation displays maximum intensity as a result of constructive interference. British physicist Sir William Henry Bragg and his son Sir William Lawrence Bragg developed a simple relation for scattering angles, now call Bragg’s law.

which relates the angle θ between a crystal plane and the diffracted X-ray beam, the wavelength λ of the x-rays, the crystal plane spacing d, and the diffraction order n (any integer).

The diffraction experiment as presently considered is intended to provide quantitative information on the lattice constant and shape characteristics of the unit cell.