If I try it in the simplest of terms it has got more to do with how ehtylene is formed (by the oxidation of ethane). When a molecule of C2h6 is oxidized as the first equation depicts, it takes away two electrons from each carbon(or an H atom with two electrons), now each carbon has to form another bond to make up for the 'lost-electrons' and one way it can do it is by forming another bond with the other carbon.
You are starting to get it. What happens is that 2 electrons are removed from ethane, not
from each carbon. Also 2 hydrogen's are removed from ethane as you can see from the equation for oxidation( I said 1 hydrogen in the previous post, my mistake). This means that the remaining pair of electrons must be shared between the carbons as it was once shared between that carbon and one of the hydrogens.
Draw ethane. erase one of the bonds to hydrogen and remove two hydrogens. you will see that if you take this new lone pair and move it over in between the carbons to form a double bond, ethylene will be formed.
Now let's just wind the clock back a bit, we had four sp3 orbitals(in an c2h6), three of which already have bonded and there's one sp3 orbital left(from where the carbon-hydrogen bond was broken because of oxidation of C2h6). Common sense would say that now since each carbon has an 'idle' sp3 orbital these should just join linearly and form another sigma bond(as I had speculated) but that is not the case and which is exactly what bothers me.
One reason it doesn't form a sigma bond is that there is already a sigma bond there. meaning there are already electrons directly in between the two carbons atoms (Physicists would kill me for this explanation, but it's a good learning tool). If you were to try to push more electrons into that space you would meet with firm resistance because doing so would destabilize the molecule.
Because of this the electrons lay over top of the sigma bond forming the pi bond. does this make sense?
in my mind you are way ahead of your age. The reason I say Physicists or even some Chemists might be upset is because electrons do not "sit in between the atoms" they move around.
I think(and I can be absolutely incorrect with this hypothesis), that another sp3-sp3 bond isn't possible because there's another sp3-sp3 bond and it would repulse another one being there pushing away the newly formed bond and making it a pi bond. But this hypothesis doesn't explain how an sp3 orbital(left by the taking away of hydrogen from each carbon) turns into a p orbital for the pi bond and what happens to the 's part of sp3' orbital.
it is said that a carbon atom is sp3
hybridized when it is tetrahedral in shape. Meaning that all three p orbitals making up the x,y,and z axis's are involved in bonding. When those 2 electrons are removed, and you do the drawing I mentioned earlier and remove the protons as well, then make the double bond, the molecule is said to be sp2
hybridized. This is because now one axis is not involved in bonding, let's say that is the z axis. your molecules is not planar, as in, in the plane of the page.
I think what you are getting tripped up on is the terminology. that Pz orbital (axis) was hybridized with the other axis in bonding, now there is nothing on the Pz axis, so you cannot refer to it as sp3
I understand that pi bonds are merely orbitals overlapping sideways, so couldn't it just be the sp3 orbitals making the pi bonds? why did it have to be the p orbitals doing that? I know I am complicating things here, and which reminds me of this
(https://www.youtube.com/watch?v=wMFPe-DwULM) That there is no answer to a 'Why'. Is it the case with my question too or is there actually an explanation?
Because now the z axis is not involved so you don't refer to it as sp3
I hope this helps, you are asking lots of good questions that are hard to explain. I'm glad AWK has answered as well.