Why does salt form when sodium and chlorine react

Why does salt form when sodium and chlorine react  

Ionic interactions are electrostatic by nature, and occur between ions of opposite charge. The overwhelming majority of ionic compounds are solids, although a few biological exceptions do occur. Table 2.7 lists a few typical properties of ionic compounds. 

It is generally unwise to think of ionic compounds as holding together with physical bonds it is better to think of an array of point charges, held together by the balance of their mutual electrostatic interactions. (By mutual here, we imply equal numbers of positive and negative ions, which therefore impart an overall charge of zero to the solid.) 

Ionic compounds generally form following the reaction of metallic elements non-metals rarely have sufficient energy to provide the necessary energy needed to form ions (see p. 123). 

The electron has transferred and in no way is it shared. Sodium chloride is a compound held together with an ionic bond, the strength of the bond coming from an electrostatic interaction between the positive and negative charges on the ions. 

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