Ceramics Are Formed By What Type Of Bond
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Ceramics are formed by what type of bond. They are either ionic in character involving a transfer of bonding electrons from electropositive atoms to electronegative atoms or they are covalent in character involving orbital sharing of electrons between the constituent atoms or ions. Graphene is currently considered the strongest known material. The two most common chemical bonds for ceramic materials are covalent and ionic. In each molecule the bonds between the atoms are strong but the bonds between molecules are usually weak.
In ionic bonding a metal atom donates electrons and a nonmetal atom accepts electrons. A material held together by either type of bond will tend to fracture before any plastic deformation takes place which results in poor toughness in these materials. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. These chemical bonds are of two types.
Electronegativity is the capability of the nucleus in an atom to attract and retain all the electrons within the atom itself and depends on the number of electrons and the distance of the electrons in the outer shells from the nucleus. This electron transfer creates positive metal ions cations and negative nonmetal ions anions which are attracted to each other through coulombic attraction. Ceramics can vary in opacity from very translucent to very opaque. For metals the chemical bond is called the metallic bond.
Recall that the predominant bonding for ceramic materials is ionic bonding. A common definition of a ceramic is a hard material that is held together with ionic and covalent bonds. Ceramic materials are usually ionic or covalent bonded materials and can be crystalline or amorphous. The primary difference between ceramics and other materials is the chemical bonds that hold these materials together.
These bonds are defined by a cloud of shared electrons with the ability to move easily when energy is applied. Noncrystalline the more translucent it will appear and the more crystalline the more opaque. According to this definition elemental carbon is a ceramic. The high energy of covalent bonds makes these ceramics very stable with regard to chemical and thermal changes.
Many ceramic materials have covalent bonds. The atoms in these ceramics are arranged so that each pair of nearest neighbour atoms forms a chemical bond by sharing a pair of electrons. Compounds with covalent bonds may be solid liquid or gas at room temperature depending on the number of atoms in the compound. Underlying many of the properties found in ceramics are the strong primary bonds that hold the atoms together and form the ceramic material.
The ionic bond occurs between a metal and a nonmetal in other words two elements with very different electronegativity. Additionally carbon based materials such as carbon fiber carbon nanotubes and graphene can be considered ceramics. The atoms in ceramic materials are held together by a chemical bond. Although they can contain covalent bonds such as the si o si linkages in glass they are often characterized by ionic bonds between positive and negative ions.