What is IUPAC name of $$[\mathrm{Co}(\mathrm{H}_2 \mathrm{O})(\mathrm{NH}_3)_5] \mathrm{I}_3$$ ?

What is effective atomic number of $$\mathrm{Pt}$$ in $$\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_4\right]^{2+}$$ ? (Given atomic number of $$\mathrm{Pt}=78$$)

Which of the following complexes is diamagnetic and square planar?

Identify the number of unpaired electrons present and geometry respectively of [Co(NH$$_3$$)$$_6$$]$$^{3+}$$ complex.