Chemistry terms and meanings continued……..
f subshell – A subshell that corresponds to the angular momentum quantum number l = 3, found in the fourth and higher principal energy levels. Each contains seven orbitals.
f orbital – A f orbital corresponds to an electron orbital with angular momentum quantum number l = 3.
face-centered cubic – A crystal unit cell that is cubic in shape with identical atoms at each corner and in the center of each face.
Example: Calcium and strontium form this type of unit cell, as do many of the transition elements.
facilitated diffusion – Facilitated diffusion is the spontaneous transport of molecules or ions across a membrane with the aid of transmembrane integral proteins.
Faraday constant – a unit of electrical charge denoted by F which is widely used in electrochemistry and equal to ~ 96,500 coulombs.
It represents 1 mol of electrons, or the Avogadro number of electrons: 6.022 × 1023 electrons. F = 96 485.339 9(24) C
Faraday’s law of electrolysis – a two part law that Michael Faraday published about electrolysis
- the mass of a substance altered at an electrode during electrolysis is directly proportional to the quantity of electricity transferred at that electrode
- the mass of an elemental material altered at an electrode is directly proportional to the element’s equivalent weight.
Fahrenheit – The Fahrenheit temperature scale was developed by Daniel Fahrenheit (1686-1736) and denoted by the symbol °F.
Ferrate – Ferrate is a polyatomic ion with formula FeO42-.
Fermium – Fermium is the name for the element with atomic number 100 and is represented by the symbol Fm. It is a member of the actinide group.
Fermentation – Fermentation is a class of chemical processes that produce energy through oxidation reactions with organic compounds.
Ferric – Ferric is a deprecated chemistry term for the iron ion with a +3 oxidation state or Fe3+.
Ferrous – Ferrous is a deprecated chemistry term for the iron ion with a +2 oxidation state or Fe2+.
Ferrum – Ferrum is the Latin name for the element iron. Ferrum is the source for iron’s symbol Fe.
Filtration – Filtration is a mechanical or physical process to separate solid particulates from fluids. A method of removing an insoluble solid from a liquid. The liquid particles and any dissolved particles are small enough to fit through the holes in a filter paper. An undissolved solid has particles that are too big to do so.
Fire retardant – A fire retardant is a compound used as an additive to reduce the flammability of a material. Example: Aluminum hydroxide is a fire retardant used in material coatings.
First Law of Thermodynamics Definition: The law which states that the total energy of a system and its surroundings remains constant. The change in the energy of a system equals the heat flow in the system from the surroundings minus the work done by the system on the surroundings. Also known as the Law of Conservation of Energy.
Fission – Fission is the splitting of an atomic nucleus into two or more lighter nuclei accompanied by energy release. The original heavy atom is termed the parent nucleus and the lighter nuclei are daughter nuclei. Fission is a type of nuclear reaction which may occur spontaneously or as a result of a particle striking an atomic nucleus.
Flame Test – A flame test is an analytical technique to identify the presence of metal ions in a sample by heating the sample with a flame and examining the color of the flame.
Flammable – Flammable is a property of a material relating how easily the material ignites or sustains a combustion reaction
Flash point – Flash point is defined as the lowest temperature the vapor of a liquid initiates a combustion reaction.
Flow – Another word for move. It is often used to describe the movement of lava.
Fluorescence – Fluorescence is luminescence that occurs where the energy is supplied by electromagnetic radiation, usually ultraviolet light. The energy source kicks an electron of an atom from a lower energy state into an “excited” higher energy state; then the electron releases the energy in the form of light (luminescence) when it falls back to a lower energy state. Examples – fluorescent lights, the red glow of rubies in sunlight, phosphors in television screens.
Fluorination – Fluorination is a chemical reaction where a fluorine atom is integrated into a molecule.
Fluorine – Fluorine is the name for the element with atomic number 9 and is represented by the symbol Fl. It is a member of the halogen group.
Fluorocarbon – A fluorocarbon is an organic compound that contains one or more fluorine atoms.
Also Known As: organofluoride, organofluorine, fluoridated hydrocarbon
Example: Fluoroethylene or vinyl fluoride is an fluorocarbon.
Formalin – Formalin is an aqueous solution of formaldehyde.
Fossil – The remains of an animal or plant that have been turned into rock and preserved. They are only found in sedimentary rocks (since the changes that produce metamorphic and igneous rocks would destroy any fossils)
Fossil record – A method of dating rocks by looking at the types of fossil taht are present and matching them to samples from elsewhere. It can also help in identifying the movement of continental plates.
Fraction – A set of hydrocarbons with similar boiling points that is produced by the fractional distillation of crude oil.
Fractionating column – Used in the fractional distillation of crude oil. It is hotter at the bottom. Crude oil is heated to form a vapour which is then passed in at the bottom of the fractionating tower.
Frequency – number of cycles per unit of time. Unit: 1 hertz = 1 cycle per 1 second
Free electron – A free electron is defined as an electron not bound to an atomic nucleus.
Freeze-thaw – When water turns to ice, it expands. If some water is trapped in a crack in a piece of rock, the freezing can cause more damage to the rock. If this process is repeated many times, the rock can be broken down. This is an example of physical weathering.
Freezing point – The freezing point is the temperature at which a liquid becomes solid. It is the same value as the melting point.
Freezing point depression – It can be used to identify a substance and it also shows that a liquid is not pure. It explains why salt is spread on the icy roads. Salt solution has a lower freezing point than pure water.
Friable – Friable is a property where a material is easily crumbled or broken down into smaller pieces.
Examples: Styrofoam and sandstone are friable materials.
Fuel – A substance that can be burned to release energy. When considering energy resources, fuels are often divided into renewable and non-renewable fuels. Renewable fuels are those whicvh can be replaced fairly quickly (such as alcohol which is formed from fermenting sugar from fast growing sugar cane).
Fuel cell – A fuel cell is a device that converts the chemical energy of a source fuel into electrical energy.
Fullerene – Fullerenes are carbon molecules arranged to form spheres, tubes or ellipsoids.
Example: Spherical fullerenes, C60, are known as buckyballs .
Full range naptha – Full range naptha is a type of naptha distilled from 5- to 12-carbon hydrocarbons boiled between 30 °C and 200 °C.
Fungicide – A fungicide is a compound which kills fungi. Fungicides are antifungal compounds.
Functional Group – A functional group is a specific group of atoms within a molecule that is responsible for characteristic chemical reactions of that molecule.
Furanose – A furanose is a five member ring structure containing four carbon atoms and one oxygen atom. Furanose is a simple sugar molecule.
Fusion – Combining lighter atomic nuclei to form a heavier nucleus. Energy is released.
Galvanic cell – battery made up of electrochemical with two different metals connected by salt bridge
Gas – particles that fill their container though have no definite shape or volume. Gas is one of the three states of matter. In a gas, the particles are a long way apart and are able to move freely. The particles bounce off each other and off the walls of the container. A gas cannot hold its own shape and will fill any container in which it is put.
Gay-Lussac’s Law – The expression Gay-Lussac’s law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes.
Gel – A gel is a sol in which the solid particles are meshed such that a rigid or semi-rigid mixture results.
Geiger-Müller counter – A device used to measure the rate of radioactive decay. A type of radiation detector.
Glass – It is made from sodium carbonate, limestone and sand. Other materials can be added to give the glass special properties.
Geochemistry – Geochemistry is the scientific study of the chemical composition of the Earth and other planets. It includes analysis of the chemical composition and reactions involving rocks, minerals and soils; the cycles of matter and energy in the earth, water, and air; and the ongoing processes that formed the Earth and change it.
Gibbs Energy – value that indicates the spontaneity of a reaction (usually symbolized as G)
Global dimming – There is some evidence that the production of particulates during the combustion of fossil fuels is causing the sun’s rays to be reflected away from the Earth.
Global warming – Many people are worried that the average temperature of the Earth is increasing. Some scientists believe that this is nothing to worry about because the Earth’s average temperature has always been changing both up and down. Other scientists are very worried because they believe that the temperature is rising too fast and will not go down again after a time.
If global warming becomes serious, the sea levels will rise (as more ice melts at the North and South Poles. There wil be climate change too (because the wind and sea currents will change).
Glycosidic Bond – A glycosidic bond is a covalent bond that joins a carbohydrate to another functional group or molecule. A substance containing a glycosidic bond is termed a glycoside. Glycosides may be categorized according to elements involved in the chemical bond.
Example – An N-glycosidic bond connects the adenine and ribose in the molecule adenosine. The bond is drawn as a vertical line between the carbohydrate and the adenine.
G-coupled Protein Receptor – A G-protein coupled receptor is a type of cell surface protein that is coupled to G-proteins (guanosine triphosphate or GTP-binding protein). G proteins are a family of similar proteins located in the cell’s plasma membrane that bind to activated complexes and undergo conformational changes by binding or hydrolyzing GTP to modify channel gates in the cellular membrane. In this way, the cell surface receptors are said to be coupled to intracellular responses.
Graham’s Law – Graham’s Law is a relation which states that the rate of the effusion of a gas is inversely proportional to the square root of its density or molecular mass.
Rate1 / Rate2 = (M2 / M1)1/2
Rate1 is the rate of effusion of one gas, expressed as volume or as moles per unit time.
Rate2 is the rate of effusion of the second gas.
M1 is the molar mass of gas 1.
M2 is the molar mass of gas 2.
Grain – This is a tiny piece of rock. They are usually rounded because they have been greatly weathered.
Granite – This is an igneous rock that has large crystals. It has formed slowly as the molten rock (magma) cooled inside other rock. Compare it wirth basalt.
Gravimetric Analysis Definition – Gravimetric analysis is a collection of quantitative analysis laboratory techniques based on the measurement of an analyte’s mass.
One example of a gravimetric analysis technique can be used to determine the amount of an ion in a solution by dissolving a known amount of a compound containing the ion in a solvent to separate the ion from its compound. The ion is then precipitated or evaporated out of solution and weighed.
Greenhouse effect and greenhouse gas – The Sun’s energy is trapped by the Earth’s atmosphere. It is said to be a contributor to global warming. Many gases can cause global warming but carbon dioxide and methane are the most talked about. If people use a lot of energy that has been provided by burning fuels, they are responsible for releasing large amounts of carbon dioxide into the atmosphere.
In recent years, the term “carbon footprint” has been used to try to help people understand that we all have a share in this problem.