The simplest organic
compounds contain molecules composed of carbon and hydrogen. The
compound methane contains one carbon bonded to four hydrogens.
Ethane is another example of a simple hydrocarbon. Ethane contains
two carbon atoms and four hydrogen atoms. In chemistry we use
a molecular formula to show how many atoms of each element are
present in a molecule. A molecular formula however does not show
the structure of the molecule. Scientists often use structural
formulas to show the number and arrangement of atoms in a compounds.
Below the molecular formula for methane and ethane are shown.
Above the molecular formula are their respective structural formula.
Although structural formulas can be very helpful
they do not give a complete picture of a molecule. Structural
formulas do not tell us anything about the distances between bonds,
the angles formed by these bonds, or the size and shape of the
molecule. Scientists use three different representation to show
what molecules look like.
THE WIRE FRAME MODEL
This model clearly shows the type of atoms in the molecule, the
distances between bonds, and angles associated with the atoms.
Because the lines drawn are very thin, molecules can very easily
be manipulated when viewed on a computer screen.
THE BALL-AND-STICK MODEL
Atoms are represented by balls and bonds are represented as
THE SPACE FILLED MODEL
This model shows the space that the molecule will take up.
Because of all the points required to draw this molecule on a
computer screen you should expect these molecules to be very difficult
structures will require you to download a molecular modeling viewer
to view the pdb files. We highly reccommend you take a look at
"Viewing Molecules at Home and School"
and download a software package.
For a more complete list of carbon compounds see
the MathMol Library