CHEMISTRY GLOSSARY

atomic absorption spectroscopy    →   atomska apsorpcijska spektroskopija

Atomic absorption spectroscopy (AAS) An analytical technique in which a sample is vapourised and the nonexcited atoms absorb electromagnetic radiation at characteristic wavelengths.

atomic spectroscopy    →   atomska spektroskopija

Atomic spectroscopy is an expensive analytical method which uses absorption (AAS), emission (AES) and fluorescent (AFS) characteristics of the analyte.

atomic orbital    →   atomska orbitala

Atomic orbital is a wave function that describes the behaviour of an electron in an atom.

atomic weight    →   atomska težina

See Relative atomic mass.

infrared spectroscopy    →   infracrvena spektroskopija

Infrared (IR) spectroscopy is a technique used for determining the structure (and sometimes concentration) of molecules by observing how infrared radiation is absorbed by a sample.

Dalton’s atomic theory    →   Daltonova atomska teorija

Dalton’s atomic theory is a theory of chemical combination, first stated by John Dalton in 1803. It involves the following postulates:

1. Elements consist of indivisible small particles (atoms).

2. All atoms of the same element are identical; different elements have different types of atom.

3. Atoms can neither be created nor destroyed.

4. ’Compound elements’ (i.e. compounds) are formed when atoms of different elements join in simple ratios to form ’compound atoms’ (i.e. molecules).

Dalton also proposed symbols for atoms of different elements (later replaced by the present notation using letters).

relative atomic mass    →   relativna atomska masa

Relative atomic mass (A_r) is the ratio of the average mass per atom of the naturally occurring form of an element to 1/12 of the mass of nuclide ¹²C. The term atomic weight is synonymous with the relative atomic mass.

spectroscopy    →   spektroskopija

Spectroscopy is the analysis of the lines of light emitted from excited atoms as the electrons drop back through their orbitals. These lines give the energy and distances of the electronic orbitals.

unified atomic mass unit    →   unificirana atomska jedinica mase

Unified atomic mass unit (u or m_u) is a unit of mass used in atomic, molecular, and nuclear science, defined as the mass of one atom of ¹²C divided by 12. Its approximate value is

AAS    →   AAS

AAS is abbreviation for atomic absorption spectroscopy.