A panic attack is an exaggeration of your bodyâs normal response to fear, stress or excitement. It is the rapid build-up of overwhelming physical sensations, such as: 1  a pounding heartbeat. 2  feeling faint. 3  sweating. 4  nausea (feeling sick).
Since four elements must be present for the combustion process to occur (fuel, heat, an oxidizing agent, and a chemical chain reaction), a fire can be extinguished by removing any one of these four elements.
Example Combustion Reactions. A simple example of a combustion reaction is the reaction between hydrogen gas and oxygen gas to produce water vapor: 2H2(g) + O2(g) â 2H2O(g) A more familiar type of combustion reaction is the combustion of methane (a hydrocarbon) to produce carbon dioxide and water: