15. Summary

It is a fact that the materials are different, the most interesting point in chemistry’s view is that why?
1. As earlier mentioned, one reason is that all atoms have different amount of electrons.
2. Amount of electrons on outermost shell is the next one. The atoms differ from each other: Group 1 atoms have only one electron on their outermost shell and therefore they can donate this electron to get an octet. But in groups 3-12 the situation is different. For example Chromium has also 1 electron on it’s outermost shell but on next shell 13 electrons so therefore it cannot react very easily because donating 1 electron does not help to create an octet.
3. An atom can have different amount of neutrons like H has.(isotope)
4. The structure of molecule is different. Although the number of all atoms is similar but the structure is different, is the material different, (isomer) like 1-pentanol C5H12O and pentanol C5H11OH.
5.One of the main characteristics of a molecule is its geometry often called its structure. While the structure of diatomic, triatomic or tetra-atomic molecules may be trivial, (linear, angular pyramidal etc.) the structure of polyatomic molecules, that are constituted of more than six atoms (of several elements) can be crucial for its chemical nature.One good example of that is Carbon which can appear as a diamond, fullerene and graphite.
6.Metals have different property for oxidation. K, Ca, Na, Mg, Zn, Fe, Sn, Pb, H, Cu, Hg, Ag, Au, Pt. They are here ordered from base to noble and the more far they are from each other the more ability to react with each other they have.