posted by Jam09 .
Hello! my question is.
Cumulene has chemical formula C4H4 with 7sigma and 3pie bonds. the 2 outer C atoms have a hybridization of "sp2", the H atoms have a hybridization of "s", and the 2 C atoms in between have "sp" hybridization. As I figured out, there has to be 3 sets of hybridizations, s/sp2 , sp/sp2 , and sp/sp. But there is another one which is p/p hybridization. Where did this p/p hybridization come from? and what does it mean?
The first and fourth carbon atoms are sp2 hybridized. The second and third carbon atoms are sp hybridized. There is no need to assume the hydrogen atoms are hybridized.
Hybridization is a scheme to explain the geometry around a central atom bonded to two or more other atoms. Each of the four C atoms is a central atom with sp2 or sp hybridization. Your reference to "hybridization sets" makes no sense.
Each of the four carbon atoms has a non-hybridized p-electron The four p-electrons form an extended π-electron system (cloud) which does not alter, or adds to the sp2 and sp hybridizations mentioned.