Some chemistry:: I am trying to understand the meaning of each question...help me!!?

Question

1. wat is the diff. btwn molecular orbital, valence bond theory & atomic orbital?

2. what is hybrid orbitals

3. The important facts of the IMF

4. what is dipole moment

Answer 1

You need to understand that the atomic orbitals are only rigorously correct for hydrogen atom, a single proton and single electron atom. All these n, l, m quantum numbers and energy levels are the solutions of Schrödinger equation for hydrogen atom. Since these orbitals can be used on other atoms and even molecules to explain many things, we then have molecular orbital theory.
(1) Atomic orbitals are the orbitals around every atom. The electrons of the atom occupies the atomic orbitals with the lowest energies. Their shapes and energy levels are arranged according to certain rules. When two or more atoms combined to form a molecule, the out-most atomic orbitals of one atom would deform and rearrange to form bonds with the out-most atomic orbitals of the other atoms. The newly formed orbitals calls molecular orbitals. When the electrons in a molecular orbital is well shared by both atoms forming the bond, this bond calls valence bond.
(2) When the simple molecular orbital theory can not explain certain phenomenon, the molecular orbital theory must be modified. Hybrid orbitals are these modified ones. Normally, several bonding molecular orbitals mix and deform and rearrange to form the same amount of hybrid orbitals.
(3) IMF, or the intermolecular forces, including here in the order of the strength: charge-charge, dipole-dipole, polar-polar (and mixed one such as dipole-polar), and London dispersion, can be used to explain many physical properties of materials such as the melting point and boiling point. To use it, one needs first understand the materials.
(4) A dipole moment forms when two opposite charge are separated by a very small distance. The interaction of a dipole moment in cases like charge-dipole and dipole-dipole, are fundamentally charge-charge interactions. But since dipole are so common and important, it has been discussed separately.