What do the thicker and dotted bond lines mean in H₂O₂?

[FeDeX_LaTeX]

Hello;

I don't understand the symbols drawn on this diagram;

http://upload.wikimedia.org/wikipedia/commons/8/8e/Wasserstoffperoxid.svg

I understand that the bond between the two oxygen atoms is a single sigma bond (illustrated by a -), but what are the bonds between the oxygen and hydrogen atoms on both sides (a thicker, triangular bond line and dotted lines)?

Thanks.

 

[Rajini]

hi,
it is just a representation to understand that the bond, which connects H and O, are perpendicular to each other!

 

[sjb-2812]

See perhaps http://courses.chem.psu.edu/chem210/tutorials/stereo-drawings/stereo-tutorial.html or similar - I wouldn't go so far as to suggest perpendicular, and indeed I don't think the relevant dihedral angle in hydrogen peroxide is 90 degrees.

 

[Borek]

Not perpendicular, just one is below the surface while another is above. Most often these are tetrahedral, but not necessarily, there is no rigid convention behind.