Difference Between Lanthanides and Actinides

Main Difference

The main difference between Lanthanides and Actinides is that Lanthanides are those chemical elements of f block of the periodic table which do not form the complexes easily whereas Actinides are those chemical elements of f block of the periodic table which can form the complexes easily.

Lanthanides vs. Actinides

f block elements are elements in which the last electron enters in f orbital of their atoms. These elements are also characterized as the inner transition elements. They consist of two series which include the lanthanides and the actinides. The lanthanide series is the series of chemical elements which comprises of 15 metallic chemical elements that contain atomic numbers 57 through 71, from lanthanum through the lutetium. The actinide series, on the other hand, is the series of chemical elements which comprises of 15 metallic chemical elements that contain atomic numbers from 89 to 103, actinium through the lawrencium.

Lanthanides are considered as the non-radioactive elements except for the Promethium. All actinides, on the flip side, are regarded as the radioactive elements because of the unstable nature they have.

Comparison Chart

LanthanidesActinides
The chemical elements are present in the lanthanide series of f block in the periodic table are called lanthanides.The chemical elements which are present in the actinide series of f block in the periodic table are called actinides.
Atomic Number
The atomic number of the elements present in the lanthanide series ranges from 57 to 71.The atomic number of the elements present in the actinide series ranges from 89 to 103.
Position in Periodic Table
In the periodic table, lanthanides are located in the lanthanide series of f block.In the periodic table, actinides are located in the actinide series of f block.
Oxidation States
The oxidation states shown by the lanthanides are +2, +3, and +4.The oxidation states shown by the actinides are +3, +4, +5, and +6.
Maximum Oxidation State
The maximum oxidation state shown by the lanthanides is +4.The maximum oxidation state shown by the actinides is +6.
Radioactivity
Lanthanides are considered as the non-radioactive elements except for the Promethium.All actinides are considered as radioactive elements because of their unstable nature.
Oxocations
Lanthanides are not involved in the formation of oxocations like oxides and hydroxides.Actinides are responsible for the formation of oxocations like oxides and hydroxides.
Basic Behavior
Lanthanides show less basic behavior.Actinides show more basic behavior.
Chemical Activity
Lanthanides exhibit less tendency towards the formation of complexes.Actinides exhibit a stronger tendency towards the formation of complexes.
Coloring Effect
Almost all of the ions which are formed by the lanthanides are colorless.Most of the complexes formed by the actinides are colorful.
Toxicity
Lanthanides are not toxic compounds.Actinides are regarded as toxic compounds because of their heavy metal behavior and radioactivity.
Valence Electrons
The valence electrons of lanthanides are located in the 4f orbital.The valence electrons of actinides are located in the 5f orbital.

What are Lanthanides?

Lanthanides are those chemical elements of f block of the periodic table which do not form the complexes easily. The atomic number of lanthanides ranges from 57 to 71. As they are the metallic elements, so they get oxidized in the moist air. They are also able to get quickly dissolve in acids. Lanthanides can react with oxygen and halides, but this reaction takes place slowly. They are not capable of showing a +6 oxidation state. That’s why they cannot form complex molecules. Lanthanides are regarded as electropositive elements. Therefore, they offer priority to make molecules with the electronegative elements. But the changes in the physical and chemical properties are very less throughout the series.

What are Actinides?

Actinides are those chemical elements of f block of the periodic table which can form the complexes easily. The atomic number of actinides ranges from 89 to 103. The abundant and most common actinides found on earth are Thorium and Uranium. They release high energy during the radioactive decay. The prominent oxidation state that is shown by actinides is +3. Actinides make the hydroxides and basic oxides. They are capable of forming complexes with ligands such as sulfates, chlorides, etc. Most of the complexes formed by actinides are colorful. But actinides are regarded as toxic compounds because of their heavy metal behavior and radioactivity.

Key Differences

  1. The chemical elements are present in the lanthanide series of f block in the periodic table are called lanthanides, whereas, the chemical elements which are present in the actinide series of f block in the periodic table are called actinides.
  2. The atomic number of the elements present in the lanthanide series ranges from 57 to 71; on the other hand, the atomic number of the elements present in the actinide series ranges from 89 to 103.
  3. In the periodic table, lanthanides are located in the lanthanide series of f block. Conversely, in the periodic table, actinides are located in the actinide series of f block.
  4. The oxidation states shown by the lanthanides are +2, +3, and +4, on the flip side, the oxidation states shown by the actinides are +3, +4, +5, and +6.
  5. The maximum oxidation state shown by the lanthanides is +4; on the other side, the maximum oxidation state shown by the actinides is +6.
  6. Lanthanides are considered as the non-radioactive elements except for the Promethium, while, all actinides are considered as the radioactive elements because of their unstable nature.
  7. Lanthanides are not involved in the formation of oxocations like oxides and hydroxides; on the other hand, actinides are involved in the formation of oxocations like oxides and hydroxides.
  8. Lanthanides show less basic behavior, whereas actinides show more basic behavior.
  9. Lanthanides exhibit less tendency towards the formation of complexes, on the flip side, actinides exhibits a stronger tendency towards the formation of complexes.
  10. Almost all of the ions which are formed by the lanthanides are colorless; on the other hand, most of the complexes of the actinides are colorful.
  11. Lanthanides are not toxic compounds. Conversely, actinides are regarded as toxic compounds because of its heavy metal behavior and radioactivity.
  12. The valence electrons of lanthanides are found in the 4f orbital, on the other side, the valence electrons of actinides are found in the 5f orbital.

Conclusion

The above discussion summarizes that lanthanides are regarded as non-radioactive elements and have some exceptions, whereas, actinides are the radioactive elements. The former could not form the complexes easily, whereas the latter could form complexes easily.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss

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