Σ and ∏ bonds and hybridization

[member 392791]

I am having difficulties understanding the concept of hybridization and the σ and ∏ bonds. My current understanding is that basically you just mix up a p and s orbital and it gives you an sp orbital, and if the bonds touch they are σ bonds, and if the bonds are parallel the are ∏ bonds. I don't see the motive for this theory or what the upshot of all this mumbo jumbo is. Can anyone help clarify? Same with valence bond theory vs. MO theory

 

[Infinitum]

Hybridization theory was brought in because when you viewed a CH₄ molecule, you'd see all the C-H bonds had equal bond lengths and equal angles between them. The original theory of each orbital making its own bond with the other did not yield this, since, s-s, s-p, formed in CH₄ would be of different lengths. So basically, to make the theory in acceptance of the observed details, this new idea was introduced.

Now with this hybrid theory, you get 4 of s-p bonds which was decided to be called sp₃ as one s and 3 p are involved.

This might also be helpful to get a broader picture,
http://chemistry.boisestate.edu/people/richardbanks/inorganic/bonding%20and%20hybridization/bonding_hybridization.htm