Covalent bond






 1.    Covalent bond:     
A chemical bond formed when two atoms share one or more pairs of electrons with each other.


       2.    Ionic bond:
 A chemical bond formed when one atom gains and a second atom loses electrons. An ion is a molecule or atom that has lost one or more electrons and is, therefore, electrically charged.



       3.    Hydrogen bond:
 A chemical bond formed between two atoms or ions with opposite charges.



       4.    Polar bond:
A covalent bond in which one end of the bond is more positive than the other end.



       5.    Double bond:
A covalent bond consisting of two pairs of electrons.



       6.   Triple bond:
A covalent bond consisting of three pairs of electrons.


       7.    Multiple bond:
A double or triple bond.



        8.    Electronegativity:
 A numerical method for indicating the relative tendency of an atom to attract the electrons that make up a covalent bond.