Types Of Bonds

There are thress basic ways in which chemical combination occurs:

(1)    IONLIC  or ELECTROVALENT BOND.

(2)    COVALENT BOND

(3)     COORDINATE BOND.

(1)    IONLIC  or ELECTROVALENT BOND.


    IONLIC  or ELECTROVALENT BOND are formed by transfer of valence electrons from one atom to another. this type of bond unites two atoms one of which has excess electrons than the stable  number (2 or 8) , and the  other is short of electrons. sodium chloride is a typical  compound formed in this way.

Here the sodium atom (2,8,1) transfers its excess electrons to chlorine atom (2,8,7) and thus both attain a  stable inert gas type electron configuration. sodium acquires the electron configuration of neon(2,8) and becomes positively charged chlorine acquires the electrons configuration of argon(2, 8 , 8) and bcomes negatively charged. these oppositely charged ions are held together by electrostatic force of attraction.this type of bond is commonly found in inorganic  compounds.

EXAMPLE...




NOTE THAT

Ionic or electrovalent compounds are non-volatile, soluble in water and possess high melting points. their aqueous solution( aqueous solution are those solution where in inculde in water) conduct electric current.


(2)    COVALENT BOND


COVALENT BOND are formed by mutual sharing of electrons. this type of bond unites two atoms, both of which are short of electrons.
 the two atoms contribute one electron each and share the resulting pair of electrons. HYDROGEN is the simplest  compound formed in this way.

EXAMPLE


THE BOND formed in this way may be single (---- )covalent bond (==) or triple covalent bond (--- =) depending upon the number of shared electrons.such bonds  sre commonly found in organic compounds.

pic...

NOTE THAT.
Covalent compounds are volatile , generally insoluble in water but soluble in organic  solvants. they possess low melting and boiling points.their solution do not conduct  electric current.


(3)     COORDINATE BOND.

coordinate bond is also formed by mutual sharing of electrons but in this case the two electrons that sharred come from the same atom. A coordinate bond unites two atoms, one of which has a spare pair of electrons and the other is short of a pair of electrons. the first atom (donor atom) contributes one pair (lone pair) of electrons and the second atom (acceptor atom) accepts it.after the formation of the bond , the lone pair of electron is held in common. the coordinate bond is represented by an arrow, pointing away from the donor atom.An excellent illustration of the coordinate bond is found in the boron  hydride-ammonia complex .

THE FULL EXPLINATION WITH PICTURE EXAMPLE IS COOMING SOON...............!!!