w2 terms (Atomic Structure & Spectroscopy, Molecular Spectroscopy & Chromatography) Flashcards
Absorption spectroscopy
Spectroscopic techniques that measure the absorption of radiation as a function of frequency or wavelength
Bulk composition
What most of the object is made up of
Electromagnetic radiation
A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously
Element
A pure chemical substance consisting of a single type of atom distinguished by its atomic number
Emission spectroscopy
Spectroscopic techniques that measure the electromagnetic radiation emitted when electrons drop from a higher energy level to a lower energy level
Energy Dispersive X-ray Spectroscopy (EDX)
An analytical technique used for the elemental analysis or chemical characterization of a sample
Energy level
The energy of a quantum state of a system
Gamma ray
Electromagnetic radiation emitted from the nucleus of an atom by radioactive decay
Neutron Activation Analysis (NAA)
An analytical method used to determine the chemical elements comprising a material by bombarding it with neutrons to produce radioactive atoms whose emissions are indicative of the elements present
Part per billion (ppb)
1 in 1 000 000 000
Part per million (ppm)
1 in 1 000 000
Radioactive
Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction
Relative abundance
Amount of an element present in a given environment in comparison to all other elements
Scanning Electron Microscope (SEM)
A type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons
Trace impurities
What a very small portion of the object is made up of
Chromatography
Method of separating a mixture into its components
Compound
A pure chemical substance consisting of two or more different chemical elements
Infrared (IR) spectroscopy
Analysis of infrared light interacting with a molecule
Mass Spectrometry (MS)
An instrumental method for identifying the chemical constituent of a substance by means of the separation of gaseous ions according to their differing mass and charge
Mobile phase
A fluid which carries a mixture through the stationary phase
Molecule
Two or more atoms held together by chemical bonds
Retention Factor (Rf)
A numerical method to describe the position of spots, i.e. the distance travelled by the compound divided by the distance travelled by the solvent
Retention Time
The time taken for a solute to travel through the column
Stationary phase
A layer fixed in place during the chromatography process and interacts with the analytes, e.g. silica layer in thin layer chromatography (TLC)
