Complete both resonance structures of nitrous acid, hno2by adding the missing lone pair electrons, multiple bonds, and non-zero formal charges. do not add curved arrows, reaction arrows, or plus signs between the structures.

The two resonating structures of Nitrous Acid are shown below. Lone pair of electrons, single and multiple bonds and non zero formal charges (red color) are also specified.

Among these two structures the structure on the left lacking formal charge is the most stable form. The instability of second resonating structure is due to the fact that it contains two formal charges (the lesser the number of formal charges the greater is the stability). Secondly in this structure one oxygen atom is having +1 formal charge. Oxygen being more electronegative feel hostile towards positive formal charge. 

Ions gain or lose electrons

Sorry i dont understand the question can you rephase it?