CHEM 121 Chapter Notes - Chapter 4: Bond-Dissociation Energy, Ionic Compound, Lattice Energy
Document Summary
Ionic compounds are high-melting solids because of their ionic bonds. Lattice energy (is amount of energy that must be supplied to break an ionic solid into its individual gaseous ions and is thus measure of strength of solid"s ionic bonds) Molecular compounds are low-melting solids, liquids, or even gases. If attractive forces are stronger than repulsive forces, a covalent bond of formed, with 2 atoms held together and 2 shared electrons occupying region between nuclei. Chemical formula (lists symbols of compound"s constituent elements and uses subscripts to indicate number of atoms each element has) Structural formula (explicitly shows bonds between atoms between atoms and therefore gives much more information than just chemical equation) Bond dissociation energy (d) (amount of energy that must be supplied to break covalent bond between 2 atoms in an isolated molecule in gaseous state) *always positive because energy must always be added to break the bond*