Lewis Structures
The Rules
1.
2.
3.
4.
5.
6.
Calculate the total number of valence e- for the molecule. If it's a
polyatomic ion, add or subtract the charge from the total number based on
whether it's an anion or a cation.
Draw the skeleton structure for the molecule. The central atom is the least
electronegative atom. Always place a hydrogen or fluorine at the end. Also,
for oxyacids, oxygen is never the central atom, and hydrogens are bonded to
the oxygen.
Add pairs of e- in all bonds.
Take the remaining valence e- and distribute as many as needed to the
surrounding atoms until their octets are filled. Remember that H gets a
maximum of 2.
Distribute the remaining valence electrons to the central atom to fulfill its
octet. Upon distribution of all of the valence electrons, if the central atom
does not satisfy the Octet Rule, "borrow" lone pair(s) of electrons from one
or more surrounding atoms and create multiple bonds until the Octet Rule is
satisfied. If needed and if possible, draw multiple structures to indicate
resonance.
If there are remaining pairs of electrons after satisfying the Octet Rule, put
additional lone pairs on the central atom (expanded valence).
Lewis Structures
The Rules
1.
2.
3.
4.
5.
6.
Lewis Structures
The Rules
1.
2.
3.
4.
5.
6.
Calculate the total number of valence e- for the molecule. If it's a
polyatomic ion, add or subtract the charge from the total number based on
whether it's an anion or a cation.
Draw the skeleton structure for the molecule. The central atom is the least
electronegative atom. Always place a hydrogen or fluorine at the end. Also,
for oxyacids, oxygen is never the central atom, and hydrogens are bonded to
the oxygen.
Add pairs of e- in all bonds.
Take the remaining valence e- and distribute as many as needed to the
surrounding atoms until their octets are filled. Remember that H gets a
maximum of 2.
Distribute the remaining valence electrons to the central atom to fulfill its
octet. Upon distribution of all of the valence electrons, if the central atom
does not satisfy the Octet Rule, "borrow" lone pair(s) of electrons from one
or more surrounding atoms and create multiple bonds until the Octet Rule is
satisfied. If needed and if possible, draw multiple structures to indicate
resonance.
If there are remaining pairs of electrons after satisfying the Octet Rule, put
additional lone pairs on the central atom (expanded valence).
Calculate the total number of valence e- for the molecule. If it's a
polyatomic ion, add or subtract the charge from the total number based on
whether it's an anion or a cation.
Draw the skeleton structure for the molecule. The central atom is the least
electronegative atom. Always place a hydrogen or fluorine at the end. Also,
for oxyacids, oxygen is never the central atom, and hydrogens are bonded to
the oxygen.
Add pairs of e- in all bonds.
Take the remaining valence e- and distribute as many as needed to the
surrounding atoms until their octets are filled. Remember that H gets a
maximum of 2.
Distribute the remaining valence electrons to the central atom to fulfill its
octet. Upon distribution of all of the valence electrons, if the central atom
does not satisfy the Octet Rule, "borrow" lone pair(s) of electrons from one
or more surrounding atoms and create multiple bonds until the Octet Rule is
satisfied. If needed and if possible, draw multiple structures to indicate
resonance.
If there are remaining pairs of electrons after satisfying the Octet Rule, put
additional lone pairs on the central atom (expanded valence).
Lewis Structures
The Rules
1.
2.
3.
4.
5.
6.
Calculate the total number of valence e- for the molecule. If it's a
polyatomic ion, add or subtract the charge from the total number based on
whether it's an anion or a cation.
Draw the skeleton structure for the molecule. The central atom is the least
electronegative atom. Always place a hydrogen or fluorine at the end. Also,
for oxyacids, oxygen is never the central atom, and hydrogens are bonded to
the oxygen.
Add pairs of e- in all bonds.
Take the remaining valence e- and distribute as many as needed to the
surrounding atoms until their octets are filled. Remember that H gets a
maximum of 2.
Distribute the remaining valence electrons to the central atom to fulfill its
octet. Upon distribution of all of the valence electrons, if the central atom
does not satisfy the Octet Rule, "borrow" lone pair(s) of electrons from one
or more surrounding atoms and create multiple bonds until the Octet Rule is
satisfied. If needed and if possible, draw multiple structures to indicate
resonance.
If there are remaining pairs of electrons after satisfying the Octet Rule, put
additional lone pairs on the central atom (expanded valence).