bond energetics

[hassam]

why energy is released when a bond is formed ???

 

[kahynickel]

the direct answer of your question is that whenever bonds are formed energyis released so as to gain stability. A resulting compound or a molecule has lower energy than the individual compounds from which it has been made.

Now the explanation.

individual atoms when each other contain unpaired electrons means that they have high energy. when these highly energetics atoms combine they combine either by ionic or covalent bonding. In covalent bonding the two atoms share electrons in between them. For this to happen the spin of the unpaired electrons must not be same i.e the one of the electron change its direction of spin from clockwise to anticlockwise and in doing so it throws out its energy. Finally the two electrons when covalently bonded in a moleclue are then maked the molecule at low energy level.

For ionic bonding the picture is little different. Here in most cases, like the formation of NaCl, the transfer of electron happen. THe formation of an ionic compound/solid/lattice/crystal actually occurs. this is a topic of A2.

But generally you remember that whether it is ionic or covalent energy is released.