<p>hi.in kaplan i found a type which said that the oxid number of an element is given from the type n-1/2electrons which are being shared -1/2 e unshared of that atom.
but when should i use that type??for example if they ask u what is the number of S in HSO4- using the type gives you 2 and using that S+4*(-2)+1=-1 gives u 6.which one is correct??</p>