Fire – one of the most beautiful physical phenomena. And one of the most mysterious. Even today not so many people can precisely tell what the phenomenon is.
Instruction
1. Many mistakenly call burning fire, but it is wrong. Actually fire – only one of burning stages. If to speak even more particularly – it the physical phenomenon considers gases and plasma in total. At the same time the reasons of their allocation can be various – chemical reaction or explosion, ignition of combustible materials in the presence of oxidizer. One of the main properties of fire – its high ability to self-distribution in the corresponding conditions. But in certain cases, for example, during burning of chemicals, the flame is absent completely.
2. In order that there was fire, performance of three conditions is necessary at once. The first condition – availability of fuel which will burn. The following requirement consists available oxidizer thanks to which process of burning can exist. The last condition - temperature has to correspond to properties of both oxidizer, and fuel. If at least one of conditions is not observed, then burning becomes impossible therefore fire will also not arise. At observance of all requirements the burning process accompanied with fire is observed. It should be noted that fire is painted depending on a type of fuel.
3. Those which in the presence of oxidizer are capable to flare up are considered as combustible substances. Depending on properties distinguish several types of fuel. If substance cannot independently burn in the presence of oxidizer, then they are called nonflammable. And the substances capable to burn only in the presence of fire source, it is accepted to call slow-burning substances. And only those substances which can independently continue to burn even after removal of a source of fire are called combustible substances. Combustible substances can be practically in any aggregate state. Practically all substances having great combustible properties contain a number of chemical impurity. These impurity are also responsible for color which will be possessed by fire after ignition.
4. So wood has habitual orange color while red color of a flame appears at combustion of calcium or lithium. And for creation yellow it is necessary to use as fuel combustible substance with the high content of sodium. By noble blue color it is characterized when burning natural gas, blue – if at fuel there is a selenium. Presence at fuel of the titanium or aluminum gives to fire white color. Fire becomes violet-red under the influence of potassium, and under the influence of molybdenum, antimony, copper, barium or phosphorus – green.