91Ó°ÊÓ

(a) Draw the structure for \(\mathrm{Pt}(\mathrm{en}) \mathrm{Cl}_{2} .\) (b) What is the coordination number for platinum in this complex, and what is the coordination geometry? (c) What is the oxidation state of the platinum? [Section 23.2]

Two Fe(II) complexes are both low spin but have different ligands. A solution of one is green and a solution of the other is red. Which solution is likely to contain the complex that has the stronger-field ligand? [Section 23.6\(]\)

Explain the lanthanide contraction, and describe how it affects the properties of the transition-metal elements.

Sketch a plot of atomic radius versus number of valence \(d\) electrons for the period 5 transition metals, and explain the trend.

The +2 oxidation state is common for almost all the transition metals. Suggest an explanation.

No compounds are known in which scandium is in the +2 oxidation state. Suggest an explanation.

Write out the ground-state electron configurations of (a) \(\mathrm{Ti}^{3+}\) (b) \(\mathrm{Ru}^{2+},(\mathrm{c}) \mathrm{Au}^{3+}\) (d) \(\mathrm{Mn}^{4+}\).

How many electrons are in the valence \(d\) orbitals in these transition-metal ions? (a) \(\mathrm{Co}^{3+},(\mathbf{b}) \mathrm{Cu}^{+}\), (d) \(\mathrm{Os}^{3+}\). (c) \(\mathrm{Cd}^{2+}\)

Explain the difference between a diamagnetic substance and a paramagnetic substance.

Distinguish among a ferromagnetic substance, an antiferromagnetic substance, and a ferrimagnetic substance.