CHEMISTRY GLOSSARY

bohrium    →   bohrij

Bohrium was discovered by Peter Armbruster, Gottfried Münzenber and their co-workers at the Heavy Ion Research Laboratory (Gesellschaft für Schwerionenforschung, GSI) in Darmstadt, Germany in 1981. Named in honour of Niels Bohr, the Danish physicist. It is synthetic radioactive metal. Bohrium was produced by bombarding bismuth-204 with chromium-54.

ampere    →   amper

Ampere (A) is the SI base unit of electric current.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2×10^-7 newton per metre of length.

angular acceleration    →   kutna akceleracija

If the angular velocity of a body changes from an initial value ω_i to a final value ω_f, average angular acceleration, α, can be defined for the time interval Δt = t_f - t_i:

The instantaneous angular acceleration, α, is the limit of the average angular acceleration, as Δt is made to approach zero:

SI unit for angular acceleration is s^-2.

aqua regia    →   zlatotopka

Aqua regia is a mixture of one volume part of nitric acid (HNO₃) and three volume parts of hydrochloric acid (HCl). Dissolving of gold in aqua regia is described by the following equation:

boiling point elevation    →   povišenje vrelišta

Boiling point elevation is an elevation of the boiling point of a solvent is observed when substances are dissolved in it. The amount by which the boiling point is elevated is proportional to the number of molecules of solute and independent of their nature.

Bronsted base    →   Bronstedova baza

Brønsted base is a material that accepts hydrogen ions in a chemical reaction.

Bronsted-Lowry’s acid-base theory    →   Bronsted-Lowryeva teorija kiselina i lužina

Brønsted-Lowry’s acid-base theory: Acid is a substance which gives a proton (protondonor) and base is a substance which accepts a proton (protonacceptor).

buffer capacity    →   puferski kapacitet

Buffer capacity is number of moles of a strong acid or a strong base needed to change pH of 1 dm³ of buffer solution for pH unit.

californium    →   kalifornij

Californium was discovered by Stanley G. Thompson, Kenneth Street Jr. and Albert Ghiorso (USA) in 1950. Named after the State and University of California, USA. It is synthetic radioactive metal. Powerful neutron emitter. Californium was made by bombarding curium with helium ions.

angular velocity    →   kutna brzina

A point-like object that undergoes circular motion changes its angular position from initial Θ_i to final Θ_f, relative to a fixed axis, specified in a coordinate system with an origin that coincides the centre of the circular path of object. The change in its angular position is called angular displacement ΔΘ = Θ_f - Θ_i. Also, a rigid body that rotates about a specified rotation axis, changing its angular position from initial Θ_i to final Θ_f, undergoes an angular displacement ΔΘ.

The average angular velocity, ω_av, is the ratio of the angular displacement and the time interval Δt=t_f-t_i, in which that displacement occurs.

Θ_f and Θ_i are the initial and final angular position, respectively.

The instantaneous angular velocity ω is the limit of the average angular velocity, as Δt is made to approach zero.

ω_av and ω are positive for the counterclockwise rotation (in direction of increasing Θ) and negative for the clockwise rotation (in direction of decreasing Θ).

SI unit for angular velocity is s^-1.The measure for the angle Θ is radian. The relationship between radians and degrees is:

For example, the angular velocity of the minute hand of a clock is: