A diapole refers to a pair of equal and oppositely charged or magnetized poles that are separated by a distance. In Chemistry, a diapole refers to a molecule in which the concentration of the positive charge is separated from a concentration of the negative charge.
If you mean "dipole," then this refers to a substance that is polar. This means that at the particle level, one end of the representative unit of that substance has a positively charged end and a negatively charged end. Examples include all ionic compounds (like salt) and all polar covalent compounds (like water, ammonia, and hydrochloric acid.)
According to Wikipedia: "In physics, a dipole is a quantity involved some form of polarity." [sic] Diamond does not possess this characteristic.
Difference in density between covalent bonds due to Electronegativity.It basically is to do with the permanent diapoles and the net diapole that results from this and all that shizz.In other words to which atom the shared pair of electrons are pulled closer to (because of electronegativity)
The intra and inter molecular forces will help to determine the higher boiling.Intra molecular forces are Polar/Non-polar covalent bonds and ionic bonds. Covalent bonds are stronger than ionic bonds.Polar covalent bonds will have a higher boiling point because non-polar covalent bonds are only affected by London forces.Intermolecular forces are hydrogen bonding, diapole-diapole and London. All molecules have London forces.Also the higher the electro-negativity the higher the boiling point.If all of the intra and inter molecular forces are the same, refer to the electro-negativity and size. The greater the electro-negativity and size, the higher the boiling point.