The f- and d- block elements

The f-block elements:

• Lanthanides:

• Elements 57 (Lanthanum) to 71 (Lutetium)

• Also called the rare earth metals

• All are metals

• Have a silvery-white appearance

• Are soft and malleable

• React easily with oxygen, water, and acids

• Form trivalent ions (3+)

• The atomic masses is very close to each other.

• In Lanthanide series, the number of 4f- electrons increases from one to fourteen.

• Actinides:

• Elements 89 (Actinium) to 103 (Lawrencium)

• Also called the actinide elements

• All are metals

• Are radioactive Have melting points higher than lanthanides.

• Have very short half lives

• Form trivalent ions (3+)

• In Actinide series, the number of 5f- electrons increases from one to fourteen.

Similarities between f-block elements:

• All are metals

• Have large atomic and ionic radii

• Have low ionization energies

• Form basic oxides and hydroxides

• Form colored compounds

• Both the series show a gradual change in the properties known as Lanthanide contraction and Actinide contraction.

• Both exhibit variable oxidation states.

• Differences between f-block elements:

• Lanthanide ions are colorless, while actinide ions are colored.

• Actinides are radioactive whereas Lanthanides are not.

The d-block elements:

• Elements in the 18 Groups of the periodic table
• Called transition elements because of the transitional nature of their properties.
• Contains three rows that are labeled as 3d, 4d and 5d.
• Elements belonging to the 3d series are called First transition series whereas those belonging to 4d and 5d are called Second and third transition series respectively.
• There are ten 3d-transition elements, ranging from scandium (Sc) to zinc (Zn).
• The d-block elements exhibit a wide variety of colors due to the partial filling of the d-orbitals.

Similarities between d-block elements:

• All are metals (except Hg)
• All are hard and lustrous
• All are fairly high in density
• Form colored compounds
• Form complexes
• Undergo catalytic reactions

Differences between d-block elements:

• They show variation in oxidation states
• Their melting and boiling points increase on moving down a group

General properties of d- and f- block elements:

• Both d and f block elements have large atomic radii
• Both exhibit variable oxidation state:
• Variable magnetic properties
• Catalytic properties
• Complex formation
• Transition metals are used as alloys, while actinides are used for controlled chain reactions.