Which cation is most likely to be found in place of fe(ii) in the square planar binding domain of hemoglobin?

The cation that is likely to be found in place of Fe(ii) in the square planar binding domain of hemoglobin is the Cobalt ions (Co2+)
Cobalt ion is closely related to Iron (ii) ions as a transition metal and can support a square planar coordination environment. 

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

Must be negative.substance increases