chemistry notes

Chemistry NotesChemistry Notes

Covalent Bonding Covalent Bonding DiagramsDiagrams

An Addendum to Lewis An Addendum to Lewis StructuresStructures

Carbon and silicon Carbon and silicon are exceptions to the are exceptions to the pattern of how to pattern of how to place electrons in a place electrons in a Lewis Dot Structure.Lewis Dot Structure.

An Addendum to Lewis An Addendum to Lewis StructuresStructures

This is because they This is because they have hybrid orbitals have hybrid orbitals (where the s and p (where the s and p sublevels blend sublevels blend together and have four together and have four equal energy orbitals.)equal energy orbitals.)

Covalent BondingCovalent Bonding

A covalent bond occurs A covalent bond occurs between two non-metalsbetween two non-metals

Electrostatic bonding Electrostatic bonding does not occur—in other does not occur—in other words, there is no “give words, there is no “give and take” of electronsand take” of electrons

It ends up being a “tug of It ends up being a “tug of war” of electronswar” of electrons

Where the electrons end up Where the electrons end up somewhere in the middle.somewhere in the middle.

Single BondsSingle Bonds

A single bond occurs A single bond occurs when one pair of when one pair of electrons is shared by electrons is shared by two atoms.two atoms.

This pair of bonded This pair of bonded electrons is called a electrons is called a shared pairshared pair. .

Double and Triple Double and Triple BondsBonds

Double bonds occur Double bonds occur when two atoms have two when two atoms have two shared pair of electronsshared pair of electrons

Triple bonds occur when Triple bonds occur when two atoms share three two atoms share three pair of electronspair of electrons

Covalent Bonding Covalent Bonding DiagramsDiagrams

Like the ionic bonding Like the ionic bonding diagrams, first draw the dot diagrams, first draw the dot diagram for each elementdiagram for each element

Now, however, the electrons Now, however, the electrons are not being given away or are not being given away or taken, but shared; so signify a taken, but shared; so signify a pair being shared by circling pair being shared by circling both electrons.both electrons.

Covalent Bonding Covalent Bonding DiagramsDiagrams

Every element should Every element should have eight electrons have eight electrons (count each shared pair as (count each shared pair as two).two).

If there is more than one If there is more than one of each element in the of each element in the compound, you have to compound, you have to have a have a central atomcentral atom..

Covalent Bonding Covalent Bonding DiagramsDiagrams

The center atom The center atom will be the one with will be the one with the most spots to the most spots to bond to.bond to.

HydrogenHydrogen

Since hydrogen is in Since hydrogen is in the first energy level, the first energy level, it will not need 8 it will not need 8 valence electrons to valence electrons to be stable—it will only be stable—it will only need 2.need 2.

HH22

HH22OO

ClCl22

OO22

NN22

CClCCl44

COCO22

HCNHCN

PClPCl33

HH22OO22

CC22HH44

CSFCSF22

COCO