[thedy]

Hi,I have a problem,which I cannot solve.I beat brains for a long time....but nothing,I am hopeless...
So,my problem involve drawing of Lewis structures and general look,what electrons do,when they form bond....
I have read so many high school chemistry books,but everyone is copy of the each other.I have few questions,I know,you give on this forums only hints,but in my case,there is nothing with my laziness to do.I need change my view on some chemistry sections.
First question:I give example of ordinary molecule,HNO3.In my way,if I want to piece together some molecule,like this,I keep track on electron configuration of atom,that is in molecule.
So,in case of HNO3,nitrogen is central atom,and has five valence electrons:three unpaired electrons,which can form bonds.In p(x) orbital is one unpaired electron(keep on mind Hund s rule),in p(y) is one,and in p(z) is one too.And nitrogen has also electron pair in s orbital.So total is  5.Hydrogen atom is clear.And now,oxygen atom.It has six valence electrons.Two unpaired electrons  in p(y) and in p(z) orbital.Oxygen has also two lone pairs.One is in s orbital, and second in p(x)orbital.
Now,I m going to draw Lewis structure.I have two options.First.
In centre is Nitrogen.One unpaired electron will form bond with first Oxygen.Second unpaired electron of Nitrogen forms next bond with second Oxygen.And third unpaired electron of Nitrogen produces third bond.Hydrogen is bonded to one of three oxygen.
So now:Nitrogen has now three single bonds with oxygen,and has also one lone pair in s orbital.
Oxygens:First Oxygen has one bond with Nitrogen and one bond with Hydrogen.So it has two lone pairs.Second oxygen has one bond with Nitrogen,second unpaired electron is free,and  second Oxygen has also two lone pairs,like first Oxygen.Third oxygen has one bond with Nitrogen,one unpaired electrons and in the end two lone pairs.So,two oxygens have one unpaired electrons.What they can do?How can they form bond with nitrogen,if Nitrogen has only lone pair.Can be this lone pair split,or something?Or is this one of possible structure?Is it radical?
Now second option:
Everything is like in first option but,Second oxygen makes two bonds.So that means,second Oxygen has only two lone pairs and third Oxygen has two unpaired electrons,it doesn  t form bond with Nitrogen.Nitrogen can should form dative bond,but Oxygen doesn t have free orbital.So is it possible to take one unpaired electron from,for example p(y) orbital,and put it to p(z)orbital to make one free orbital p(y)?
So this is my two options,how to make Lewis structure of HNO3,but it doesn t work,like we can see,because in first option we get two Oxygens with two unpaired electrons,and in second option we get one Oxygen with one unpaired electrons.
And now,I will write,what says all high school chemistry book:Count all valence electrons,keep octet rule.That s all.But it is not enough,for me.It must be something beyond this.
I have one idea:Electrons can mix together,like they want.But it is total crazy,voodoo chemistry.Then,for what  does exists orbitals,quantum mechanis,if it doesn t matter,which electrons are in orbital and which are paired and which not? Every high school teaches,that lone pairs cannot form bond (except dative bond),and cannot be split.Or my other idea is,that Lewis structure cannot be form from atoms by oneself.But why?
I m sorry that my question is so large,but I had to write everything,what have been on my mind.If you can,try answer me something,some help,hint or something.And if you know some chemistry book,where is exaplained my problem,where are answers for my questions,please recommend...
Thank you very much,thanks for patient.

[fledarmus]

Nitrates, nitrites, and organic nitro groups are odd ducks in the Lewis structure book. These appear to be sp² hybridized, but the nitrogen contributes a pair of electrons to one of the sp² orbitals. This gives three orbitals in a plane at 120^o, two of which have one electron, and one that has two electrons. The remaining electron is in the p(z) orbital, above and below the plane.

So in the case of HNO₂ (nitrous acid, parent of nitrite ion), nitrogen is sharing one electron with each oxygen in a sigma bond (120^o apart). It is sharing a second electron with one of the two oxygens to form a pi bond, and the other oxygen is sharing an electron with a hydrogen atom. The nitrogen still has a lone pair, 120^o from and in the same plane as the two oxygens. The nitrogen and both oxygens have a full octet of electrons.

In the case of HNO₃, that lone pair contributes both electrons as a dative bond to a third oxygen atom. Formally, this is usually written as a single bond with a positive charge on the nitrogen and a negative charge on the oxygen, although it is not an ionic bond. The nitrogen and all three oxygens have a full octet of electrons.

For the organic nitro group, it is essentially the same as HNO₃, except that the bond to the -OH group is replaced with bond to a carbon atom. Nitrogen is still formally positive, one oxygen has a sigma and a pi bond with the nitrogen, and the other oxygen has a dative bond, taking both electrons from the nitrogen "lone pair". Nitrogen and the two oxygens all have a full octet. Nitrogen has a formal positive charge and one oxygen has a formal negative charge, but since the two oxygens are otherwise identical and two redundant resonance structures can be drawn, the structure is typically shown as:

[Jasim]

Read up on ions. This is nitric acid, you are correct in your thinking, you can't draw a covalent, non-charged structure.

It might be easier to see if you split the ions apart as they would be in a solution, H⁺ and NO₃^-.

You will have a single bond from the nitrogen to one of the oxygens, leaving that oxygen with an extra (total three) lone pairs, which gives it a negative formal charge.

EDIT: Fledarmus beats me again
The structure Fledarmus posted is much more representative of what is actually taking place.

[thedy]

In the case of HNO₃, that lone pair contributes both electrons as a dative bond to a third oxygen atom. Formally, this is usually written as a single bond with a positive charge on the nitrogen and a negative charge on the oxygen, although it is not an ionic bond. The nitrogen and all three oxygens have a full octet of electrons.

Thanks,but I don t understand,if lone pair contributes both electrons to third oxygen,it means,that third oxygen has still two unpaired electrons,has not?
EDIT:
But now,I see,that you are talkin about hybridized orbitals.
One more question:Can I piece together individual atoms to form molecules?That means,I keep track on electron configuration.It is not enough to count valence electrons and assign them to atoms according to octet rule.Am I right?

[fledarmus]

One more question:Can I piece together individual atoms to form molecules?That means,I keep track on electron configuration.It is not enough to count valence electrons and assign them to atoms according to octet rule.Am I right?

I'm not sure exactly what you're asking here, but I'll try to answer what I think you're asking. Lewis structures are a shorthand, quick and dirty way of determining the number of bonds, the type of bonds, and the number of lone pair electrons. For most cases, these structures are very fast and very helpful, and you don't need to go any further to answer your questions. There are a few structures, however, where you need to go deeper into molecular orbitals and overlaps to get a good view of what is happening; there is information in molecular orbital theory which is not reflected in Lewis structures, and sometimes you need that extra information.