Notes to Supplement --- Organic Chemistry
Chemistry I, and AP Chemistry
Mr. von Werder, WLHS
The Element Carbon
► The element carbon has properties that allow it to make up tens thousands of molecules, many of
which are essential to the existence of life.
Allotropes of carbon
Allotrope
◼ different forms of the same element (as opposed to isotope… or isomer…)
◼ due to different bonding patterns or arrangements
◼ different forms usually have significantly different chemical and physical properties
Some of the more familiar carbon allotropes:
◼ Diamond
• Each carbon is bonded to four other carbons; tetrahedral geometry (see model)
• Strong and stable arrangement of the bonds makes diamond very strong and hard.
• Uses; ornamentation and jewelry, as tips on cutting tools, coatings
◼ Graphite
• Carbon atoms are bonded in sheet-like fashion (see model)
• ‘Sheets’ are weakly bonded to each other - slip over each other easily (lubricant)
• Mixture of graphite and clay is used to make pencil “lead”
◼ Amorphous carbon
• Amorphous (“a” – without; “morph” – shape)
• This form of carbon has no predictable arrangement of its atoms
• Charcoal, soot, bone black, coke
◼ Fullerenes
• Globe shaped, cage like arrangements of carbon atoms (see model).
• Also known as “buckyballs” (named geodesic dome engineer R. Buckminster Fuller)
• Recently discovered (couple of decades ago); uses are still being researched.
Unique Bonding of Carbon
Carbon has four outermost (valence) electrons
◼ Allows it to typically form four covalent bonds to achieve a stable octet of electrons
Carbons has a relatively small size – its valence electrons are relatively close to the nucleus
◼ This small size allows for short strong covalent bonds to form (single, double, triple)
Carbon can form long chains of carbon bonded to carbon, bonded to another carbon, etc.
◼ These chains, with other atoms bonded here and there, allow carbon to be the backbone to
thousands of different molecules. (Examples…)
