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: Combustion is the formation of CO 2 and H 2 O from the reaction of a chemical and O 2 Combination (synthesis): Combination is the addition of 2 or more simple reactants to form a complex product.