He added a couple of drops of iodine and nothing happened. finally, he added a cople of drops of cobalt thiocyanate and nothing happened. using the table abovel, what substance did dr. goodchem find?

He added a couple of drops of iodine and nothing happened. finally, he added a cople of drops of cobalt thiocyanate and nothing happened. using the table abovel, what substance did dr. goodchem find?