explain all steps please

Part (a) [35 Marks] Using the structures of the clinical diagnostic 99mTc agents Cardiolite and Ceretec shown below: i. Identify the oxidation sate of both metal ions. ii. Explain the role of complex charge toward their bio-distribution properties. iii. Contrast their ligand coordination environments with respect to complex stability in vivo. iv. Using the structure of Ceretec only, predict the possible pharmacokinetic effects of substituting the peripheral methyl group (shown in red) with the following R groups; acetic (CH2COOH), isopropyl (CH(CH3)2), and benzyl