Sodium chloride, NaCl, is formed when a sodium atom transfers its electron to a chlorine atom. The difference in charge between the two atoms creates a(n) electrostatic attraction that bonds them together.
Sodium being a metal has 1 extra electron whereas chlorine being a non-metal is electron deficient. As a result, in order to complete their octet sodium will transfer its one electron to chlorine.
As a result, sodium becomes positively charged and chlorine will become negatively charged. Thus, there will be formation of an ionic bond between sodium and chlorine.
This opposite charge on both these atoms will cause an electrostatic repulsion between the two.
Thus, we can conclude that the difference in charge between the two atoms creates a(n) electrostatic attraction that bonds them together.
We divide the thin rectangular sheet in small parts of height b and length dr. All these sheets are parallel to b. The infinitesimal moment of inertia of one of these small parts is where Now we find the moment of inertia by integrating from to The moment of inertia is (from (-a/2) to (a/2))
to 
(from (-a/2) to
(a/2))