d and f BLOCK ELEMENTS

Which element listed explicitly adopts a cubic close-packed (ccp) structure in the 4d series?

• Niobium
• Molybdenum
• Ruthenium
• Palladium

What does the ability of Iron (Fe) to adopt both bcc and ccp structures indicate about transition metals?

• They are always amorphous.
• They only ever have one structure.
• They are unstable.
• Some transition metals can exhibit polymorphism, having multiple stable crystal structures.

Based on the text's description, which transition metal series would you expect to generally have the highest melting points?

• 3d series
• 4d series
• Lanthanide series
• 5d series

Why might the melting point of Technetium (Tc) be considered anomalous according to the text?

• It has a very high melting point.
• It has a completely filled d orbital.
• It is a liquid at room temperature.
• Its melting point does not follow the expected maximum near the d⁵ configuration.

Which property of transition metals is LEAST directly related to the involvement of d electrons in bonding?

• High melting point
• High enthalpy of atomisation
• High electrical conductivity
• Metallic lustre