Chapter 1
Carbon
Makes up less than 1% of the Earth’s crust
o Si, Al, O2 are most prevalent
Not all carbon-containing material is considered organic
o Some inorganic carbon-containing materials are pure carbon (graphite, diamond,
Bucky Balls, nanotubes), carbon dioxide, calcium carbonate, etc.
Carbon is unique in that it forms strong single bonds with itself
o This is why it is able to form so many different structures.
Principles of Atomic Structure
Isotopes – differing number of neutrons
Ions – differing number of electrons
Elements – differing number of protons
Formal charge
Formal charge =Valence-# of bonds-# of nonbonding electrons
o Formal charge for this oxygen= 6valence-3bonds-2non-bonded electrons=+1
If you were asked for the formal charge of oxygen in this number you would
need both the positive and the number.
A lot of students will either write just + or just 1.
o You’ll only get half credit because when asked for the formal
charge you need to put both the sign and the value.
, To make it easier on yourself, recognize the common bonding patterns of some
commonly seen elements
o The elements below those in the charts often have the same bonding patterns as
those above them.
Ex. Sulfur is below oxygen, and it frequently has two bonds and two lone
pairs in stable, neutral compounds.
Bonding patterns for common neutral,stable atoms
Boron Carbon Nitrogen Oxygen Fluorine
Bonds 3 4 3 2 1
Lone Pairs 0 0 1 2 3
Bonding patterns when C, N, O, or F are positively charged
Carbon Nitrogen Oxygen Fluorine
Bonds 3 4 3 2
Lone Pairs 0 0 1 2
Bonding patterns when negatively charged
Boron Carbon Nitrogen Oxygen Fluorine
Bonds 4 3 2 1 0
Lone Pairs 0 1 2 3 4
Lewis Structures
We’re not going to go through and count all the electrons for these.
Instead, we’re going to use the bonding patterns above.
Ex. CH3COCH2CH2NH3
o “CH3” always looks like this:
Carbon
Makes up less than 1% of the Earth’s crust
o Si, Al, O2 are most prevalent
Not all carbon-containing material is considered organic
o Some inorganic carbon-containing materials are pure carbon (graphite, diamond,
Bucky Balls, nanotubes), carbon dioxide, calcium carbonate, etc.
Carbon is unique in that it forms strong single bonds with itself
o This is why it is able to form so many different structures.
Principles of Atomic Structure
Isotopes – differing number of neutrons
Ions – differing number of electrons
Elements – differing number of protons
Formal charge
Formal charge =Valence-# of bonds-# of nonbonding electrons
o Formal charge for this oxygen= 6valence-3bonds-2non-bonded electrons=+1
If you were asked for the formal charge of oxygen in this number you would
need both the positive and the number.
A lot of students will either write just + or just 1.
o You’ll only get half credit because when asked for the formal
charge you need to put both the sign and the value.
, To make it easier on yourself, recognize the common bonding patterns of some
commonly seen elements
o The elements below those in the charts often have the same bonding patterns as
those above them.
Ex. Sulfur is below oxygen, and it frequently has two bonds and two lone
pairs in stable, neutral compounds.
Bonding patterns for common neutral,stable atoms
Boron Carbon Nitrogen Oxygen Fluorine
Bonds 3 4 3 2 1
Lone Pairs 0 0 1 2 3
Bonding patterns when C, N, O, or F are positively charged
Carbon Nitrogen Oxygen Fluorine
Bonds 3 4 3 2
Lone Pairs 0 0 1 2
Bonding patterns when negatively charged
Boron Carbon Nitrogen Oxygen Fluorine
Bonds 4 3 2 1 0
Lone Pairs 0 1 2 3 4
Lewis Structures
We’re not going to go through and count all the electrons for these.
Instead, we’re going to use the bonding patterns above.
Ex. CH3COCH2CH2NH3
o “CH3” always looks like this:
