To draw the Lewis structure of covalent molecules/ions following steps are followed: i) Identify the central atom in the given species. Generally central atom is that atom which is less in number, usually electronegativity of central atom is less. Hydrogen is never a central atom ii) Atoms which are directly attached with central atoms are called surrounding atoms. iii) Arrange the surrounding atoms around central atoms and make a single bond between each pair of central and surrounding atoms. If by adoing so the octet of surrounding atoms is not complete, them make double or triple bond to ensure that the octet of all the surrounding atoms is complete, keeping in mind the covalency of central atoms. Usually covalency of any element is the number of unpaired electrons either in ground or in excited state. iv) Covalency of any of the second period element can never exceed four i.e., it can't have more than eight electrons in its valency shell. However, covalency of 3rd and lower period elements can be less than, equal to or greater than four. v) Represent the lone pair of electron particularly of central atom vi) If the given species is polyatomic ion then before making any bond between central atoms and surrounding atoms distribute the charge on surrounding atoms symmetrically as far as possible and then follow all the above mentioned steps. Which of the followrng structures of (CN_(4))^(2-) is incorrect ?