Why do atoms bond
Atoms bond together in a process that we can term ‘happy atoms’ and this basically means that all atomic shells require to be full. This means that a delicate balance must be maintained within the atoms though some atoms have perhaps one or two extra electrons which they will give up. To do so, these overfull atoms seek out other atoms that require an electron. For example, for atoms with atomic numbers between 1 and 18 there exists something known as the 2-8-8 rule, and it basically means that the first shell contains two electrons, the second shell contains eight electrons and the third shell contains eight electrons also. In this range we can look a bit more closely at sodium and magnesium (Na and Mg, respectively).
Taking our example of happy atoms these two atoms also wish to be happy in the same way, and in order to become so there are two possibilities open to them: First, they can attempt to find eight electrons which would fill up their third shell, or they could choose to give up several electrons in order to have a filled second shell. In such an instance it would be easier for them to relinquish several electrons. This scenario would work very well, as there exist plenty of other atoms that would wish to receive a few extra electrons.
Two good examples of elements seeking a couple of extra electrons in order to make up a filled shell are Oxygen and Fluorine. Each of these elements have one filled shell comprising two electrons, however their second shell desires eight electrons. In order to obtain the extra electrons they can either share electrons, or they can borrow them-making bonds. In the case of a sodium atom with an extra electron and a fluorine atom seeking an extra atom they can work together to form a bond and, in our hypothesis, become happy atoms. Sodium would relinquish its extra electron, thereby having a full second shell whilst affording Fluorine a full second shell also. Another way in which these two can bond together is to wither give up or share electrons. By doing so, they would have created something called an electrovalent bond.
Because atoms also require the electron and neutron content to be equal this prevents them from separating again immediately after the electron sharing process is complete. In order for the electrons to successfully fill in the second shells of both Flourine and Sodium both atoms must remain in close proximity, thus forming a bonded molecule. This molecule can continue to expand in many cases as well depending on the atom and its specific needs. Carbon, for example, is well-known for its versatility and ability to form many complex chains through the electron sharing process and because of this has become the key component in life on our planet. Other molecules such as water (H2O) share weaker bonds, but because of this weaker bond are excellent regulators in energy levels in systems – hence why our bodies are 70% water and our planet’s ecosystem relies upon water to function and regulate temperatures.