Materials containing metals such as copper, aluminum, gold and silver consist of metallic bonds, while materials with transition metals such as iron and nickel are composed of both covalent bonds and metallic bonds.
Metallic bonds are strong electrostatic attractions that bind metal atoms. Since metals have low ionization energy the electrons can move freely. Therefore, in a metal bond, there is a sea of delocalized valence electrons surrounding the positive atomic nuclei. These electrons are attracted toward the positively charged atomic nuclei forming a metal lattice. Due to this arrangement, metals have unique properties such as shiny metallic luster, electrical and thermal conductivity, malleability, ductility, high tensile strength, hardness and opaqueness. Also, since the strength of metallic bonds is intermediate to that of ionic bonds and covalent bonds, metals have melting points and boiling points in between that of the ionic and covalent compounds. The low volatility and high density of metals can also be attributed to the strong attractive forces. Zinc, cadmium and mercury, which are Group-7 metals, are considered exceptions to these arrangements. Metallic bonds are non-directional bonds. These bonds are also weak because of the simultaneous attraction of valence electrons to a large number of atomic nuclei.Learn More
Calcium chloride, or CaCl2, is composed of two Cl- anions ionically bound to a central calcium atom. Calcium has a 2+ charge, and the two chlorine ions each have a 1- charge. Forming ionic bonds with calcium, the chlorine ions achieve full valence electron shells and satisfy the octet rule.Full Answer >
One example of an ionic bond is table salt, which is the compound sodium chloride. Some other examples of ionic bonds include iron oxide (rust), calcium chloride (rock salt), sodium fluoride (toothpaste fluoride) and sodium hydroxide (lye).Full Answer >
Ionic, covalent and metallic bonds are all different types of chemical bonds. Chemical bonds are formed when a chemical compound is created through the joining of multiple atoms. Ionic bonds are formed when an electron moves from one atom to another, and covalent bonds are formed when two different atoms share one or more pair of electrons. Metallic bonds are best described as a sea of electrons.Full Answer >
Larger atoms with complex electron orbitals, such as those found in the transition metals, are able to exceed the octet rule under the right conditions. In particular, these occur when the heavier elements are bonded to small, highly electronegative elements like fluorine, chlorine or oxygen. One example is phosphorus pentachloride, a single phosphorus atom bound to five chlorine atoms, which has 10 shared electrons in its outer valence shell.Full Answer >