Carbon as Central Element

With regard to their chemical structure, adhesives are to be assigned to the organic compounds. In contrast to inorganic chemistry, which treats matters of the inanimate nature (e.g., minerals, metals), organic chemistry deals with compounds of carbon as the central element of diverse matters that make up the animate nature (e.g., plant and animal products such as wood, proteins, resins, fats, petroleum). 

The special feature of carbon, and thus its dominating position among all known elements, is the fact that an almost unlimited number of compounds with carbon itself and with a multitude of other elements is possible. Each carbon atom (atoms are the smallest components characteristic for the properties of an element) shows four arms it can spread to form a bond. In chemistry, these arms are depicted by simple lines and, derived from the Latin word valentia = power, strength, they are called valencies  

These valencies or bonding possibilities between individual carbon atoms result in long chains, 

Applied Adhesive Bonding A Practical Guide for Flawless Results. Gerd Habenicht Copyright 2009 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-32014-1 

The formation of two bonds between two carbon atoms is possible as well, 

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