atom
The smallest particle that constitutes the matter of an element
Proton
A particle in the nucleus of an atom that carries a positive electrical charge.
Neutron
A particle in the nucleus of an atom that has no electrical charge.
Electron
Negatively charged particles that orbit the nucleus of an atom.
Oxidation
Chemical process that occurs when a substance combines with oxygen.
Molecule
Two or more atoms joined together in a fixed proportions.
Matter
The substance or substances of which all physical things are composed. It occupies space, has weight, and can be measured. It exists a a solid, liquid, or gas.
Exothermic
Chemical reaction between two or more materials that change the materials and produces heat.
Chain reaction of self-sustained combution
When a fuel is heated to the point that it releases flammable vapors, which burn and generate more heat on the fuel, which releases more flammable vapors.
Pyrolysis
The chemical decomposition of a substance by heat.
Vapor Pressure
The pressure exerted on the walls of a closed container by a liquid when the number of molecules escaping form the liquid reaches an equilibrium with the number of molecules returning to the liquid.
Flash Point
Minimum temperature at which a liquid gives off enough vapors to form an ignitable mixture with air near the liquid's surface.
Ignition temperature or fire point
The temperature at which the liquid will emit vapors at a rate that will support a sustained flame after the ignition source is removed. The Ignition temperature or fire point is slightly above the flash point temperature.
Normal atmospheric pressure
The pressure of the atmosphere as sea level is 14.7 pounds per square inch.
Vapor density
Weight of a given volume gas compared with the weight of an equal volume of dry air at the same temperature and pressure.
Specific gravity
Weight of a substance compared with the weight of an equal volume of water at a given temperature.
Energy
The capacity to do work.
British thermal unit
The amount of heat required to raise the temperature of one pound of water at 60 degrees F by 1 degree F at constant pressure.
Absolute zero
The temperature at which all molecular movement ceases. -459.67 degrees F.
Absolute temperature
Temperature that is measured from absolute zero.
Specific heat
The amount of heat required to raise the temperature of a specified quantity of material by 1 degree C.
Latent heat
The amount of heat energy absorbed or released by a substance when it change physical states without a change in temperature.
Latent heat of fusion
The amount of heat absorbed by a substance when converting from a solid to a liquid at the same temperature.
Latent heat of vaporization
The amount of heat absorbed by a substance when converting form a liquid to a gas or vapor at the same temperature.
Heat sink
A material that has the ability to absorb and store heat and release it after the environment cools.
Spalling
When heat allows moisture in concrete to expand, causing the concrete to crack or break away from the structure.
Heat of combustion
Total amount of thermal energy that could be generated by the combustion reaction if a fuel were completely burned.
Caloric (calorific) value
The amount of heat necessary to raise the temperature of one gram of water by 1 degree Celsius.
Stoichiometric reaction
A reaction in which all reactants are present in fixed definite proportions for the reaction to go to completion. leads to the most violent combustion.
Fire load
The amount of fuel in a compartment expressed in pounds per square foot obtained by dividing the amount of fuel present by floor area.
Fire flow
Quality of water available for firefighting in a given area.
Rate of heat release
The speed at which a fuel releases its caloric value when burning.
Endothermic reactions
Chemical reactions in which substances absorb heat energy.
Hydrophoric materials
Materials that react with water.
Pyrophoric materials
Materials that react with air.
Static electricity heating
The heat generated by static electricity arcing.
Type I combustion
Direct oxidation. Pyrolysis or decomposition of the matter is not required to occur in order to sustain combustion.
Type II combustion
Sequential oxidation. The molecular structure of the substance must be broken down to produce combustible gases, which will react with oxygen in the air.
Fire Tetrahedron
Identifies the four basic components required for the combustion process to take place. Fuel, oxygen, heat, and chemical chain reactions.
Flashover (Rapid fire progress event)
Stage of a fire at which all surfaces and objects within a space have been heated to their ignition temperature and flame breaks out almost at once over the surface of all objects in the space.
Backdraft event
Instantaneous explosion or rapid burning of super heated gases that occurs when oxygen is introduced into an oxygen-depleted space.
Resistance
The opposition to the flow of an electric current in a conductor component.