Lewis Model of Bonding

Polarity

in the bond increases with increasing difference in electronegativity between the bonded atoms.

Lewis

model: electrons in covalent bond functions in 2 ways simultaneously → shared between 2 atoms and fills the outer valence of each.

Covalent bonds

are formed between atoms that share one or more pairs of electrons to give a noble gas configuration to each atom.

Electronegativity

: a measure of an atoms attraction for electrons that it shares in a chemical bond with another atom.

EN

varies somewhat depending on the chemical environment and oxidation state of an atom.

direction of bond polarity

The is shown with an arrow, the arrowhead pointing toward the neg end and a plus sign by the pos end.

Ions

form if the difference in EN is 1.9 or greater.

dipole moment

Bond : a vector quantity that measures the polarity of a covalent bond.

Isomers

: same molecular formula, diff arrangement of atoms.

Electron affinity

: energy released upon addition of an electron.

Atoms

acquire complete valence shells in 2 ways: ionic bonds and covalent bonds.

ionic salts

The attraction between ions allows to form a strong crystal lattice and high melting point.

Ions

are formed by the transfer of electrons from the valence shell of an atom of electronegativity to the valence shell of an atom of higher electronegativity.

covalent bonds

Nonbonding electrons: valence electrons not involved in forming .

Atoms acquire complete valence shells in 2 ways

ionic bonds and covalent bonds

Electronegativity

a measure of an atoms attraction for electrons that it shares in a chemical bond with another atom

Electron affinity

energy released upon addition of an electron

Lewis model

electrons in covalent bond functions in 2 ways simultaneously → shared between 2 atoms and fills the outer valence of each

Bond length

the distance between nuclei participating in a covalent bond

Polar covalent bonds

share electrons unequally

Bond dipole moment

a vector quantity that measures the polarity of a covalent bond

Isomers

same molecular formula, diff arrangement of atoms

Bonding electrons

valence electrons involved in forming a covalent bond

Nonbonding electrons

valence electrons not involved in forming covalent bonds

Formal charge

the charge on an atom in a polyatomic ion or molecule

Formal charge = of valence electrons in the neutral nonbonded atom

(unshared electrons + 1/2shared electrons)