1、Define electronegativity.

1.Electronegativity is the relative tendency of a bonded atom in a molecule to attract electrons.The atom with a higher electronegativity value attracts the electrons more effectively.
2.Electron affinity is the energy change that occurs when an electron is added to a gaseous atom in its ground state,and its value may be positive or negative.It does not refer to bonded electrons.
3.Atoms with different values of electronegativity from polar bonds to each other.The electron density is higher near the more electronegative atom.This atom is relatively negatively charged and is assigned a partial negative charge,delta -,while the less electronegative atom is given a partial positive charge,delta +.a nonpolar covalent bond results when a bond forms between atoms having a very small or zero difference in electronegativity.