Topic 13: The periodic table - 13.1 The transition metals

Nature of science: Looking for trends and discrepancies-transition elements follow certain patterns of behaviour. The elements Zn, Cr and Cu do not follow these patterns and are therefore considered anomalous in the first-row d-block. (3.1)

Understandings

Essential idea: The transition elements have characteristic properties; these properties are related to their all having incomplete d sublevels.

Transition elements have variable oxidation states, form complex ions with ligands, have coloured compounds, and display catalytic and magnetic properties.

Zn is not considered to be a transition element as it does not form ions with incomplete d-orbitals.

Transition elements show an oxidation state of +2 when the s-electrons are removed.

Applications and skills

Explanation of the ability of transition metals to form variable oxidation states from successive ionization energies.

Explanation of the nature of the coordinate bond within a complex ion.

Deduction of the total charge given the formula of the ion and ligands present.

Explanation of the magnetic properties in transition metals in terms of unpaired electrons

Guidance

Common oxidation numbers of the transition metal ions are listed in the data booklet in sections 9 and 14.