Question

Describe the characteristics of the following groups of elements: transition metals, lanthanides, actinides.

Short answer

Transition metals, located in groups 3-12, are good conductors of both heat and electricity and possess malleability. With an incomplete d sub-shell, they can form cations with an incomplete sub-shell. Lanthanides, with atomic numbers 57 to 71, are shiny, highly conductive, and reactive metals, characterized by an incomplete 4f sub-shell. Actinides, represented by atomic numbers 89 to 103, are all radioactive and possess an incomplete 5f sub-shell. Many of these elements have no stable isotopes.

Step-by-step solution

Characteristics of Transition Metals

Transition metals are located in the d-block of the periodic table. They include groups 3-12. These metals have unique properties such as they are good conductors of heat and electricity, and they can be hammered or bent into shape without breaking (malleability). In terms of electron configuration, they have an incomplete d electron sub-shell that can give rise to cations with an incomplete d sub-shell.

Characteristics of Lanthanides

Lanthanides are located in the 6th period, the second last row of the periodic table. This series includes the 15 metallic chemical elements with atomic numbers 57 to 71, from lanthanum through lutetium. They are shiny metals, also possessing high conductivity. Many are also very reactive. In their electron configuration, they have an incomplete 4f sub-shell.

Characteristics of Actinides

Actinides are located in the 7th period, the bottom row, of the periodic table. These include the 15 metallic elements with atomic numbers from 89 to 103, from actinium through lawrencium. These elements are all radioactive. In terms of electron configuration, they have an incomplete 5f sub-shell. Many actinides have no stable isotopes.