Modern Chemistry Chemical Bonding

Introduction to Chemical Bonding

Different type of bonding give materials different properties  

Why do atoms bond? Atoms by themselves tend to have high potential energy. If they combine they can lower that potential energy and become more stable. All atoms want is to become more stable. TEKS 5a, 5b

Chemical Bond Chemical bond- link between atoms that results from the mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together. Basically positive and negatives attract!! TEK 8a

Types of chemical bonding Ionic Bonding metal with a nonmetal Transfer of electrons Covalent Bonding nonmetal with a nonmetal Sharing electrons Metallic bonding metal with a metal Atoms join through an attraction to a “sea” of electrons

Ionic Bonding Electrons are transferred from anions to cations to create an electrically neutral compound. Generally between metals and nonmetals.

Covalent Bonding Sharing of electron pairs between two atoms. Generally between nonmetals and nonmetals. TEKS 6a, 8b

The metallic bond model In metals the outer electrons are delocalized. (they move freely) The mobile electrons create a sea of electrons. Metallic bonding – The chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons.

Metallic Properties Freedom of electrons to move in metals accounts for its high electrical and thermal conductivity. Can absorb a high range of light frequencies which accounts for most metals’ shiny appearance. 5a

Malleability – ability to be hammered or beaten into thin sheets Ductility – the ability of a substance to be drawn, pulled or extruded through a small opening to produce wire

The octet Rule Octet rule – Chemical compounds tend to form so that each atom, by gaining, losing, or sharing electrons, has an octet of electrons in its highest occupied energy level.