Hybridization: "the mixing of different atomic orbitals to produce the same number of equivalent orbital, having same shape and energy is known as hybridization ". Bond energy: "the energy involved for the breaking/ formation of 1 mole of particular type of bond in the molecule is known as bond energy ". Dipole moment: "dipole moment is the product of charge and distance between positive and negative center.it is measured in Debye , however its Si unit is coulomb meter ". Molecular orbital theory : "molecular orbital theory tells that when two atomic orbitals combine to form two orbital . one molecule orbital has lower energy than other orbital and known as bonding M.o . other molecular orbital has higher than atomic orbitals and known as anti bonding M.o . Dipole -Dipole interaction : "the electrostatic force of attraction between the positive end of one polar molecule and the negative end of other polar molecule are called Dipole -Dipole interaction. Hydrogen bonding: the force of attraction between partially positive charged hydrogen atom of one molecule and lone pair of electrons of highly electric negative atom of another molecule is called hydrogen bonding. Evaporation: "at any given temperature, a certain number of the molecules in a liquid possess sufficient kinetic energy to escape from the surface.this process is called Evaporation.