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.
Combustion reactions always involve molecular oxygen O2. Anytime anything burns (in the usual sense), it is a combustion reaction.Combustion reactions are almost always exothermic (i.e., they give off heat).For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced:Wood as well as many common items that combust are organic (i.e., they are made up of carbon, hydrogen and oxygen).ombustion reactions are almost always exothermic (i.e., they give off heat). For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced: Wood as well as many common items that combust are organic (i.e., they are made up of carbon, hydrogen and oxygen).