Molecule

Molecules are elements (building blocks) of every material. Every molecule is made of atoms and has different chemical properties.

In order to distinguish those elements, scientist use two different types of labels. In written articles, scientists often use symbol-notations of molecules like H₂O (water). The second possibility is to use the so called "structural formula". By using structural formulas, it is possible to spot chemical properties and to distinguish between different molecules, which have the same symbol-notation.

Complex reactions and effects can be explained by using the knowledge about the properties about all the molecules, which are part of the reaction. For example the property of water-molecules to stick together and to push each other, which explains the effect of surface tension.

All in all the knowledge about molecules is the first step to create models of complex effects and to able to explain these effects.