Question

Compare the ways in which electrons can be donated or shared between atoms.

Answer 1

There are various ways by which electrons can be shared or donated between the atoms - that is called types of bond formation.

1) Ionic bond : It is formed when a atom (electropositive) donates it's electrons to the another atom (which has tendency to take electrons (electronegative)) . it is strong bond where complete +ve and --ve charge on the atom exists. e.g : electron transfer from Na •----> Cl . Na has one e- in their valance shell which it donates to Chlorine to form NaCl salt .

2) Covalent bond ): It is formed by sharing of electrons between the atoms . In this case electronegativity difference between the two atom is not large . e.g. in CH4 , C has 4 valance e- which it shares with 4 H to form 4 covalent bonds. There is no ion formation in this type of bond .

3) Coordinate / Dative bond : It is formed when one atom donates it's lone pair to electrons in the vacant orbital of other atom. This bond is the reason of formation of complexes. The atom / molecule which has tendency to accept lone pair of electrons are called Lewis acid and the atom / molecule which has tendency to donate lone pair of electrons are called Lewis base. e.g: H3N:-----> BF3.