Structure of Materials

There are lot of levels of structure (atomic, microscopic), many physical properties of a material are related direct to the arrangement types of bonds that make up the material, therefore the chemical structure of material is very important factor .Such topics as periodic system, types of bonding and etc. are very useful to study.

The Elements

The Elements such as copper, Iron, Zinc are materials, too. A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus. Elements are divided into metals, metalloids, and nonmetals.The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic number (number of protons in the nucleus), electron configurations, and recurring chemical properties such as melting Points

Chemical bond

A chemical bond is a tension, between atoms that allows the formation of chemical substances which contain two or more atoms. The bond is caused by the electrostatic force of attraction between opposite charges, either between electrons and nuclei, or as the result of a dipole tension.Primary Bonds or strongbonds are created when there is direct interaction of electrons two or more atoms . The strength of chemical bonds varies when there is direct interaction of electrons between two or more atoms. The more electrons per atom that take place in this process, the higher the bond order. There are four general categories of primary bonds: ionic, covalent, polar covalent, and metallic. There are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as dipole–dipole interactions.

An ionic bond ( heteropolarbond):

results when electrons are transferred from the electropositive atom to the electronegative atom, as in sodium chloride, NaCl. Ionic bonds usually result when the electronegativity difference between two atoms in a diatomic molecule is greater than about 2.0.

A covalent bond ( homopolar bond):

exist when electrons are shared between two atoms (e.g., H–H). This means that a binding electron in a covalent diatomic molecule such as H₂ .Covalent bonds are typically found in homonuclear diatomics such as O₂ and N₂ though the atoms need not be the same to have similar electronegativities. Electronegativity differences of less than about 0.4 characterize covalent bonds.

A polar covalent bond:

is formed for two atoms with an electronegativity difference of between 0.4 and 2.0.For example, hydrogen fluoride, HF.

A metallic bond:

is when elements of low electronegativity bond with each other to form a class of materials here the bonding electrons become "decentralized" and are shared by the core of positive nuclei. Metals have excellent properties such as good ductility and high thermal and electrical conductivity

Secondary bonds, or weak bonds:

occur due to indirect interaction of electrons in adjacent atoms or molecules. There are three main types of secondary bonding: hydrogen bonding, dipole–dipole interactions, and van der Waals forces.