The ligands (EDTA 4) and (CN)were used to synthesise two octahedral complex ions [Fe(CN)6]3. and [Fe(EDTA)3]2. Draw an octahedral energy diagram showing orbital splitting for each, predict the number of unpaired electrons, and identify whether the complex ion is low spin or high spin. Then, using the spin only magnetic moment equation, predict which ligand will generate the stronger magnetic complex ion. [12 marks] Explain how Technetium-99m (99mWC ) is used in medical imaging techniques such as single-photon emission computed tomography. Explain the operating principles behind these imaging techniques, as well as discussing how the 99mTc is generated for use in hospital laboratories. If a patient is administered 99mTc in advance of a scan and 99mTc has a half-life of 6.0 hours, what mass of an administered dose of 100g of 99mTc remains in a patient's body after 2.0 days? [15 marks]