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.
What is necessary for a decomposition reaction to occur? A decomposition reaction needs the addition of a catalyst or heat to proceed. For instance hydrogen peroxide will break down into water and oxygen gas in the presence of a cat â¦ alyst; and calcium carbonate will break down into calcium oxide and carbon dioxide gas when heated.