Chemistry Dictionary
Terminology "F"
- Faraday
- One faraday of electricity corresponds to the charge on 6.022 x 10 23 electrons, or 96,487 coulombs.
- Faraday's Law of Electrolysis
- One equivalent weight of a substance is produced at each electrode during the passage of 96,487 coulombs of charge through an electrolytic cell.
- Fast Neutron
- A neutron ejected at high kinetic energy in a nuclear reaction.
- Fat
- Solid triester of glycerol and (mostly) saturated fatty acids.
- Fatty Acids
- An aliphatic acid; many can obtained from animal fats.
- Ferromagnetism
- The ability of a substance to become permanently magnetized by exposure to an external magnetic field.
- Film badge
- A small patch of photographic film worn on clothing to detect and measure accumulated incident ionizing radiation.
- Flammable
- A liquid as defined by NFPD and DOT as having a flash point below 37.8°C (100°F).
- Flash Point
- The temperature at which a liquid will yield enough flamable vapour to ignite. There are various recognized industrial testing methods; therefore the method used must be stated.
- Fluorescence
- Absorption of high energy radiation by a substance and subsequent emission of visible light.
- Fossil Fuels
- Substances consisting largely of hydrocarbons, derived from decay of organic materials under geological conditions of high pressure and temperature (metamorphism) include coal, petroleum, natural gas, peat and oil shale.
- For further information see Fuel Chemistry
- Frasch Process
- Method by which elemental sulfur is mined or extracted. Sulfur is melted with superheated water (at 170°C under high pressure) and forced to the surface of the earth as a slurry.
- First Law of Thermodynamics
- The total amount of energy in the universe is constant (also known as the Law of Conservation of Energy) energy is neither created nor destroyed in ordinary chemical reactions and physical changes.
- For further information see Thermochemistry
- Flotation
- Method by which hydrophobic (water-repelling) particles of an ore are separated from hydrophilic (water-attracting) particles of a metallurgical pretreatment process.
- Fluids
- Substances that flow freely; gases and liquids.
- Flotation
- Flux
- A substance added to react with the charge, or a product of its reduction, in metallurgy; usually added to lower a melting point.
- Foam
- Colloidal suspension of a gas in a liquid.
- Forbidden Zone
- A relatively large energy separation between an insulator's highest filled electron energy band and the next higher energy vacant band. Beginning in the fourth energy level, a set of seven degenerate orbitals per energy level, higher in energy than s, p, and d orbitals of the same energy level.
- Formal Charge
- A method of counting electrons in a covalently bonded molecule or ion; counts bonding electrons as though they were equally shared between the two atoms.
- Formula
- Combination of symbols that indicates the chemical composition of a substance.
- Formula Unit
- The smallest repeating unit of a substance. The molecule for nonionic substances
- Formula Weight
- The mass of one formula unit of a substance in atomic mass units.
- Fractional Distillation
- The process in which a fractioning column is used in distillation apparatus to separate components of a liquid mixture that have different boiling points.
- Fractional Precipitation
- Removal of some ions from solution by precipitation while leaving other ions with similar properties in solution.
- Free Energy, Gibbs Free Energy
- The thermodynamic state function of a system that indicates the amount of energy available for the system to do useful work at constant T and P.
- Free Energy Change
- The indicator of spontaneity of a process at constnt T and P. If delta-G is negative, the process is spontaneous.
- Free Radical
- A highly reactive chemical species carrying no charge and having a single unpaired electron in an orbital.
- Freezing Point Depression
- The decrease in the freezing point of a solvent caused by the presence of a solute.
- Frequency
- The number of repeating corresponding points on a wave that pass a given observation point per unit time.
- Fuel Cells
- Voltaic cells in which the reactants (usually gases) are supplied continuously.
- A voltaic cell that converts the chemical energy of a fuel and an oxidizing agent directly into electriacl energy on a continuous basis.
- Functional Group
- A group of atoms that represents a potential reaction site in an organic compound.
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