Stream of positively charged particles (cations) that moves toward the negative electrode in cathode ray tubes; observed to pass through canals in the negative electrode.
Capillary
A tube having a very small inside diameter.
Capillary Action
The drawing of a liquid up the inside of a small-bore tube when adhesive forces exceed cohesive forces, or the depression of the surface of the liquid when cohesive forces exceed the adhesive forces.
Carbanion
An organic ion carrying a negative charge on a carbon atom.
Carbonium ion
An orgainic ion carrying a positive charge on a carbon atom.
Carcinogen
A substance capable of causing or producing cancer in mammals.
Catalyst
A substance that speeds up a chemical reaction without being consumed itself in the reaction.
A substance that alters (usually increases) the rate at which a reaction occurs.
Catenation
Bonding of atoms of the same element into chains or rings.
The bonding together of atoms of the same element to form chains.
The ability of an element to bond to itself.
Cathode
Electrode at which reduction occurs
In a cathode ray tube, the negative electrode.
Cathodic Protection
Protection of a metal (making ir a cathode) against corrosion by attaching it to a sacrifical anode of a more easily oxidized metal.
Cathode Ray Tube
Closed glass tube containing a gas under low pressure, with electrodes near the ends and a luminescent screen at the end near the positive electrode; produces cathode rays when high voltage is applied.
Cation
A positive ion; an atom or group of atoms that has lost one or more electrons.
Cell Potential
Potential difference, Ecell, between oxidation and reduction half-cells under nonstandard conditions.
Central Atom
An atom in a molecule or polyatomic ion that is bonded to more than one other atom.
Chain Reaction
A reaction that, once initiated, sustains itself and expands.
This is a reaction in which reactive species, such as radicals, are produced in more than one step. These reactive species, radicals, propagate the chain reaction.
Chain Termination Step
The combination of two radicals, which removes the reactive species that propagate the change reaction.
Charle's Law
At constant pressure the volume occupied by a definite mass of gas is directly proportional to its absolute temperature.
Chemical Bonds
The attractive forces that hold atoms together in elements or compounds.
Chemical Change
A change in which one or more new substances are formed.
Chemical Equation
Description of a chemical reaction by placing the formulas of the reactants on the left and the formulas of products on the right of an arrow.
Chemical Equilibrium
A state of dynamic balance in which the rates of forward and reverse reactions are equal; there is no net change in concentrations of reactants or products while a system is at equilibrium.
Chemical Hygiene Officer (CHO)
A person or employee who is qualified by training or experience to provide technical guidance in the development and implementations of the provisions of a Chemical Hygiene Plan (CHP)
Chemical Hygiene Plan (CHP)
A written program developed and implemented by an employer designating proceedures, equipment, personal protective equipment, and work practices that are capable of protecting employees from the health hazards presented by hazardous chemicals usid in that particular workplace.
Chemical Kinetics
The study of rates and mechanisms of chemical reactions and of the factors on which they depend.
Chemical Periodicity
The variations in properties of elements with their position in the periodic table
Cis-
The prefix used to indicate that groups are located on the same side of a bon about which rotation is restricted.
Cis-Trans Isomerism
A type of geometrical isomerism related to the angles between like ligands.
Clay
A class of silicate and aluminosilicate minerals with sheet-like structures that have enormous surface areas that can absorb large amounts of water.
Cloud Chamber
A device for observing the paths of speeding particiles as vapor molecules condense on them to form foglike tracks.
Coefficient of expansion
The ratio of the change in length or volumen of a body to the original lengthor volume for a unit change in temperature.
Cohesive Forces
All the forces of attraction among particles of a liquid.
Coke
An impure form of carbon obtained by destructive distillation of coal or petroleum.
Colligative Properties
Physical properties of solutions that depend upon the number but not the kind of solute particles present.
Collision Theory
Theory of reaction rates that states that effective collisions between reactant molecules must occur in order for the reaction to occur.
Colloid
A heterogeneous mixture in which solute-like particles do not settle out.
Combination Reaction
Reaction in which two substances ( elements or compounds ) combine to form one compound.
Reaction of a substance with oxygen in a highly exothermic reaction, usually with a visible flame.
Combustible
Classification of liquid substances that will burn on the basis of flash points. A combustible liquid means any liquid having a flash point at or above 37.8°C (100°F) but below 93.3°C (200°F), except any mixture having components with flash points of 93.3°C (200°F) or higher, the total of which makes up 99 percent or more of the total volume of the mixture.
Common Ion Effect
Suppression of ionization of a weak electrolyte by the presence in the same solution of a strong electrolyte containing one of the same ions as the weak electrolyte.
Complex Ions
Ions resulting from the formation of coordinate covalent bonds between simple ions and other ions or molecules.
Composition Stoichiometry
Descibes the quantitative (mass) relationships among elements in compounds.
Compound
A substance of two or more elements in fixed proportions. Compounds can be decomposed into their constituent elements.
A gas or mixture of gases having, in a container an absolute pressure exceeding 40 psi at 21.1°C (70°F)
A gass or mixture having in a container, an absolute pressure exceeding 104 psi at 54.4°C (130°F) regardless of the pressure at (21.1°C (70°F)
A liquid having a vapour pressure exceeding 40 psi at 37.8°C (70°F) as determined by ASTM D-323-72.
Concentration
Amount of solute per unit volume or mass of solvent or of solution.
Condensation
Liquefaction of vapor.
Condensed Phases
The liquid and solid phases; phases in which particles interact strongly.
Condensed States
The solid and liquid states.
Conduction Band
A partially filled band or a band of vacant energy levels just higher in energy than a filled band; a band within which, or into which, electrons must be promoted to allow electrical conduction to occur in a solid.
Conjugate Acid-base Pair
In Bronsted-Lowry terminology, a reactant and product that differ by a proton, H+.
Conformations
Structures of a compound that differ by the extent of rotation about a single bond.
Continuous Spectrum
Spectrum that contains all wave-lengths in a specified region of the electromagnetic spectrum.
Control Rods
Rods of materials such as cadmium or boron steel that act as neutron obsorbers (not merely moderaters) used in nuclear reactors to control neutron fluxes and therfore rates of fission.
Conjugated Double Bonds
Double bonds that are separated from each other by one single bond -C=C-C=C-.
Contact Process
Industrial process by which sulfur trioxide and sulfuric acid are produced from sulfur dioxide.
Coordinate Covalent Bond
Covalent bond in which both shared electrons are furnished by the same species; bond between a Lewis acid and Lewis base.
Coordinate Covalent Bond
A covalent bond in which both shared electrons are donated by the same atom; a bond between a Lewis base and a Lewis acid.
Coordination Compound or Complex
A compound containing coordinate covalent bonds.
Coordination Isomers
Isomers involving exchanges of ligands between complex cation and complex anion of the same compound.
Coordination Number
In describing crystals, the number of nearest neighbours of an atom or ion.
The number of donor atoms coordinated to a metal.
Coordination Sphere
The metal ion and its coordinating ligands but not any uncoordinated counter-ions.
Corrosion
Oxidation of metals in the presence of air and moisture.
Theory of bonding in transition metal complexes in which ligands and metal ions are treated as point charges; a purely ionic model; ligand point charges represent the crystal (electrical) field perturbing the metal?s d orbitals containing nonbonding electrons.
Amount of energy that holds a crystal together; the energy change when a mole of solid is formed from its constituent molecules or ions (for ionic compounds) in their gaseous state.
The energy charge when one mole of formula units of a crystalline solid is formed from its ions, atoms, or molecules in the gas phase; always negative.
The basic unit used to describe the intensity of radioactivity in a sample of material. One curie equals 37 billion disintegrations per second or approximately the amount of radioactivty given off by 1 gram of radium.
Cyclotron
A device for accelerating charged particles along a spiral path.
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