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# sp² hybridization

In sp² hybridization, one s orbital and two p orbitals hybridize to form three sp² orbitals, each consisting of 33% s character and 67% p character. This type of hybridization is required whenever an atom is surrounded by three groups of electrons. Created by Jay.

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• I'm still not clear on why there's an empty p orbital for BF3. Is that simply the rule whenever an atom is bonded three times, rather than four? Simply to indicate one additional bond is possible? And by that logic, would you draw two additional phantom p orbitals for an atom that could accept two additional electron pairs?
• Basically an orbital (be it s,p,d or f) is merely an area where there is a probability of finding an electron. In this case the unhybridized p orbital is of not much relevance. It is, as you mentioned, a mere phantom. Since it doesn't house any electrons it doesn not even affect the shape of BF3 as there is no electron to repel the bond pairs (VSEPR theory).

Also, here BF3 does not follow the Octet rule ( It is an exception ). So, you don't have to stick to the 8 valence electrons idea and all that. Just chill. Sal's just trying to tell you that when you create an sp2 hybrid, you take two P's (out of the Px, Py, Pz) and one 2S orbital and hybridise it, now that leaves u one unhybridised P, does it not? That' s all buddy. :)

Keep asking...... Luved ur question !
• The steric number for C2H4 would be 5 not 3 because there are 5 sigma bonds not three. 5+0=5 he leaves out the two on the right.
• When determining steric numbers you only count the bonds on one atom. The two on the right are not counted, therefore the correct number is 3.
• what is steric number?define
• The steric number is the sum of no. of sigma bonds and no. of lone pairs of electrons. It helps us to recognize what kind of hybridization is there.
When -
Steric no. = 4 , its Sp3 hybridization
Steric no. = 3 , its Sp2 hybridization
Steric no. = 2, its Sp hybridization
• for C2H4, why did it start out with one electron in the S2 orbital and and extra electron in the P orbital?
• Carbon has 4 valence electrons, and its electron configuration is 1s^2 2s^2 2p^2. Now, in order for carbon to bond appropriately 4 times you could promote an electron from the 2s orbital to the 2p orbital (thus giving you 2s^1 and 2p^3). However, these orbitals still exist at different energy levels, and thus we use hybridization.
In the case of C2H4, each carbon is bonded to 3 different molecules, and thus, we only need to have 3 hybrid orbitals; we use the 2s orbital and 2 of the 2p orbitals and the sp2 hybrid orbital is created. Under this configuration, 3 of the valence electrons are in the sp2 orbitals (the ones that bond with other atoms) while the last valence electron is in the p2 shell that was not hybridized. I'm not sure if this answers your question fully, but hopefully it'll help you figure out why there was an extra electron in the p orbital
• Is it called ethylene or ethene?
• Ethylene is the "common" name. Ethene is the "official" or "IUPAC" name. Both are acceptable but the IUPAC name is preferred.
• why are double bonds always made of one sigma and one pi bond?
why can't it be made by both sigma bonds or pi bonds?
• It is impossible to have two σ bonds because you cannot have the orbitals angled the correct way to have a second σ bond between the same two atoms.

You can have a double bond of only π bonds, but that is VERY rare (and a subject of some dispute). In any event, that is getting into very advanced chemistry that will not be covered at this level of study.

Because σ bonds are easier to form (getting the angles right for the bond to happen) and because they are stronger by having more overlap, they nearly always form before a π bond can form. So, that is one of several reasons why you nearly always have a double bond forming with one σ bond and one π bond.
• boron in BF3 molecule the B has only 3 electrons in outermost shell and after bonding with flourine the B contains total 6 electrons but according to the octet rule the B should contain 8?
• Why would there be such a thing as pi bonds? Those lone electrons in the p shell should be repelling each other, since both have negative charge. At least in a sigma bond I can wrap my mind around the fact that the electrons are actually attracted to the nucleus of the bonded atom.
• In a π bond they are still attracted to the nuclei. They are just a little off to the side of the line joining the nuclei.
• What about triple bonds with the central atoms, how many sigma bonds and pi bonds would there be?
• The same two atoms can only have one sigma bond between them. All subsequent bonds will be pi bonds.

So, the way that it works is that the first bond between the same two atoms is nearly always a sigma bond (the few exceptions are VERY obscure and you probably won't encounter them). Any extra bonds are all pi bonds.

Thus, a triple bond is one sigma and two pi bonds.