These are not molecules but each is a part of a certain molecule. The average bond lengths are given in most good general chemistry textbooks. However, the attached link gives these average values in pm (or picometer). For example, C-C has an average bond length of 154 pm.

http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html

The bond lengths given are arbitrary statistical averages which are not too useful. But we have a wonderful tool called density functional theory that will give you correct bont lengths in most of the cases. I suggest PBEsol, with a polarized DZ or TZ basis set. For simple molecules molecular mechanics might give reasonable results. And you can do your own statistics.

You can also search cccbdb database:

http://cccbdb.nist.gov/

Following Prof. Csonka's suggestion, here is the link to CCBDB database of experimental bond lengths. Just click on the names(blue colored font) to get the list of experimental bond lengths for each type.

http://cccbdb.nist.gov/expbondlengths1.asp

Dear all,

Thank you very much for your usefull links and datas. They are much useful.

Thanks alot.