Chemistry Ch8: The Basics of Chemical Bonding

ionic bonding

transfer of electrons between a metal and non-metal

covalent bonding

sharing of electrons between two non-metals

metallic bonding

bonding between 2 metals (alloys)

Octet rule

when elements react they want to have 8 electrons in their outer shell achieving noble gas configuration

electronegativity

the ability of an atom to attract electrons to itself; cornerstone of understanding behavior of atoms/electrons

EN scale

0.0-4.0 Pauling Units (Linus Pauling)

Fluorine & Francium

fluorine is the most, francium is the least. increases as you go from lower left to upper right on Periodic table

The numerical difference between any two atoms determines its

polarity

if change in electronegativity is 1.7 or greater

the bond between the two elements will be ionic. This is the case for a metal and a non-metal where the electrons are transferred. The electron is being pulled away from the least EN element to the most EN.

If less then .5

the bond is nonpolar covalent, the electrons are being equally shared

if 0.5<c. in EN<1.7

bond is polar covalent, the electrons are not being shared equally, the electrons are being pulled towards the most EN elements but not totally away from the least EN

ionic bonds are stronger than

covalent bonds

polar compounds contain

polar covalent bonds and have diploids present

either a pair of electrons is bonded or not…if not…

it is lone, unshared, or unbonded pair

bond order

the number of bonds shared between two atomsthe

the same amount of of energy it takes to make a bond is the same amount of energy

it takes to break a bond

bond length

the length of a covalent bond between two sharing nucleus. the more electron pairs being shared, the shorter and stronger the bonds

energy released or absorbed during a chemical change is due to the differences between the

reactant bond energies and the product bond energies

if there is a single bond which is ionic in the compoound

the compound is ionic

majority rules of polarity type of a compound between

polar and non-polar

both physical and chemical characteristics are to the

type of bonding present in a molecule

Formal charge (FC)

number of valence electrons (group #)-(#of bonds + # of unshared electrons

the sum of the formal charge (FC) must equal

the charge of the molecule/polyatmoic ion

FC is used to decided

which “resonant” structure is the most stablemost

most stable structure has the lowest FC on

central atom, the lowest set of numbers

rules for resonance:

a double bond must exist, ligands must be the same to move the bond

ligand

an atom which is not the central atom