for summer homework (which means "hey kids teach yourself something you've never seen while we go to the beach all summer") we got a packet on Organic Nomenclature and Simple Reactions...and there's some parts that I'm just not getting and the packet doesn't go into enough detail for me...

Question

example:
Draw the condensed formula for each of the following compounds
2, 3-dimethyl-2-butene
I don't know what it means when the numbers are separated by commas and hyphens...
I have two and a half days left and I'm just not getting it at all....

Answer 1

A condensed formula shows the functional groups in a molecule and any double or triple bonds, usually, on a single line. Here you have a a 4-carbon chain with a double bond between the 2nd and 3rd carbon. Also, methyl groups on carbons #2 and #3:
CH3C(CH3)=C(CH3)CH3
Sometimes a formula is condensed partially, showing the main carbon chain correctly in two dimensions but condensing functional groups like CH3. Since I can't show you here, see the above in the link below:
http://www.muhlenberg.edu/depts/chemistry/chem201woh/1H23dimethyl2butene.html

Answer 2

Naming an organic compound or writing its name is not something you learn in one easy lesson. There are so many groups and so many rules. You need a course in organic chemistry just to get started. AP Chemistry and General Chemistry in college cover this very lightly. Here are two links which may be helpful:
1. A nice online textbook on General, Organic, and Biochemistry. Start with the chapter on Alkanes:
http://ull.chemistry.uakron.edu/genobc/
2. For a quick lesson on naming and formula writing of organic compounds, go to:
http://www.chemguide.co.uk/basicorg/conventions/names.html

Answer 3

...okay I think I understand it!...as for the naming...oh dear...thank you so much!