LEWIS ELECTRON- DOT STRUCTURES

• The valence, or outer-shell, electrons are represented as dots surrounding the atom’s symbol.

• Take the valence electrons, distribute them as dots one at a time around the four sides of the symbol, and then pair them up until all the valence electrons are distributed.

IONIC BONDING

• The attraction of the opposite charges forms the ionic bond. The metal loses electrons to form a cation and the nonmetal becomes an anion by gaining electrons

COVALENT BONDING

• Covalent bonding is the sharing of one or more pairs of electrons. The covalent bonds in a molecule often are represented by a dash, which represents a shared pair of electrons.

• The covalent bonds in a molecule often are represented by a dash, which represents a shared pair of electrons.

• In the hydrogen molecule, the electrons are shared equally. Each hydrogen nucleus has one proton equally attracting the bonding pair of electrons. A bond like this is called a nonpolar covalent bond.

• Electronegativity (EN) is a measure of the attractive force that an atom exerts on a bonding pair of electrons.

MOLECULAR GEOMETRY- VSEPR

• One way to predict the shape of molecules is the VSEPR (valence-shell electron-pair repulsion) theory. The basic idea behind this theory is that the valence electron pairs surrounding a central atom, whether involved in bonding or not, will try to move as far away from each other as possible to minimize the repulsion between the like charges.

VALENCE BOND THEORY

• The valence bond theory describes covalent bonding as the mixing of atomic orbitals to form a new kind of orbital, a hybrid orbital.

• Hybrid orbitals are atomic orbitals formed as a result of mixing the atomic orbitals of the atoms involved in the covalent bond.

BOND LENGTH, STRENGTH, AND MAGNETIC PROPERTIES

• Paramagnetism, the attraction to a magnetic field, is due to the presence of unpaired electrons; diamagnetism, the slight repulsion from a magnetic field, is due to the presence of only paired electrons.