Please urgently reply to these questions
 

Asslam O Alikum
i will be waiting . . .
i have confusion in questions about CHEMISTRY so please help me . . .
1) Why carbon atom does not make four bonds { C::C} ?
2) after formation of bonds covalent , ionic or co ordinate covalent where electron revolve and how in their shells?
3) Valency of carbon atom in ground state is two and four in excited state from where carbon gets energy for excitation ?
Please sir reply this i am waiting for their answers and i have asked from many peoples but i have not received answers yet pleas reply this i will be thankful to you i will never forget your this thanks. . .
Thanks in Advance

Asslam O Alikum
was my thread not according to rules and regulation of the forum ? that it was moved , i had posted a thread bout one week ago but not received reply so i posted it once again and edit it but i do not know why it is moved and who moved it ? if it was not according to rules and regulation i do apology !
it is said that "it is very easy to hurt some one and say sorry but it too difficult to get hurt and say it's OK i am fine"

The answer of your first and third Q is:
the electronic configuration of C is 1s2 ,2s2 ,2px1 ,2py1 and 2pz is empty.so C has two unpaired electron for bond formation.As you know that when bonds are formed, energy is released.So in start of reaction, C form 2 bonds and energy is released after bond formation.There is only a small energy gap b/w the 2s and 2p orbitals,and so it pays the C to provide a small amount of energy to promote an electron from 2s to the empty 2pz to give 4 unpaired electrons.it would be to the carbon' s benefit to try to maximize the no.of bonds it can form.For this reason, C will form an excited state by promoting one of its 2s e' into empty 2p orbital.By forming this excited state, C will be able to form 4 bonds.

Hadi, i do not understand your 2nd question:sad::sleep:

Answer to que#2:
In Ionic bond, one atom loses electron(s) and the other gains it. In covalent bond, electrons revolve in the shells of both the atoms. Co-ordinate covalent bond is the same as covalent bond but here both the electrons come from the same atom. Hope it edifies.

thanks very much thanks . . . bundle of thanks for replying gently . . . "Naqash Fatima" i will ever remain thankful to you i also appreciate your reply about third question . . .
after thinking a lot. . . i understand that ans about question one {C::C}?
bond length decreases as bonds are formed single, double or triple if fourth will be formed that their nucleus may collide but i may be wrong . . .
as about my second question that as we know that electron revolve around nucleus in their fixed paths Shells but how they revolve after formation of bond? but i appreciate reply of "candidGuy"

Q2. In covalent bond electron wil lie in between the nuclei of the bonded atoms whie in polar covalent bond, the electron colud will be more towards the electronegative atom.
In the case of Ionic bond, electron will revolve around the electronegative atom only and in coordinate covalent bond electrons will be revolving around both the nuclei.

i will be waiting . . .
 

Asslam O Alikum
Sir
i had post reply but mistakenly i wrote my email over their which i should have not done , where you had offered that " you just mention the name of book i will mail you that" so please you can see my profile but i am hard need of Chemistry material , Sir
i am thankful to you for such kind of offer , i study in Pharmacy but have keen interest to do MSc in Chemistry with specialization in Nuclear Chemistry if not in Nuclear Chemistry than in another field of Chemistry so i will abandon Study Of Pharmacy so pleas please i will remember your thanks for ever if you mail me material of Chemistry. in periodic table there is no exact position of Hydrogen but i have assigned it, in few days i will post it also because it takes a lot time to type this is my little effort so also i would welcome positive criticism and corrections because i may be wrong . . . so i want to have as much as material of Chemistry . . . thanks a lot i will be waiting for your mail . . .

Ans to q=2 is simple.

Electrons occupy orbitals after bond formation. Either ionic,covalent or polar covalent including dative,banana,pi to pi.(excluding metallic bond as electronic sea model explains it).

Before bonding they occupy atomic orbitals and after bond formation they occupy either hybrid orbitals(according to VBT) or molecular orbitals(according to MOT). Whatever approach u take electron remains in orbital where probability is maximum.

Hello
 

Hello dear Hadi and other friends i want to clear the concept. First of you askes wher the energy comes from? The answer is very simple when atom approach each other or come in close proximity the enery of the system raises why because the positively charged protons and the negatively charged electrons offers some repulsion and energy of the system increases.
Secondly this energy help carbon to promote one of its electron to the empty Pz orbital now the three P orbitals and one S orbital combine to form four equivalent orbitals called SP3 hybridized orbitals in this way carbon forms four bonds. Finally the electron shared are always used by either of the atoms.