In the previous session, we studied about the general characteristics of lanthanides and actinides. We noticed that both lanthanides and actinides have similar outermost electronic configuration due to which they show certain similarties and differences.
Similarties between Actinides and Lanthanides –
- Both lanthanides and actinides have common oxidation state +3.
- They have high melting point and boiling point, showing magnetic and spectral properties.
- Both lanthanides and actinides have similar electronic configuration in which last electron enters in (n-2)f-subshell. Hence, they have similar properties.
- Lanthanides having lanthanide contraction and actinides having actinide contraction in which with increase in atomic number, nuclear charge increases due to which atomic size decreases.
- They are highly electropositive and very reactive elements.
- Solubility of lanthanides and actinides –
Nitrates, sulphates, perchlorates – Soluble
Fluorides, carbonates, hydroxides – insoluble
Difference between Lanthnaides and Actinides –
- All elements of actinide series are radioactive whereas elements of lanthanide series are non-radioactive except promethium.
- Actinides have maximum +6 oxidation state whereas lanthanides have maximum +4 oxidation state.
- Actnides – 89 to 103
Lanthanides – 57 to 71
- In actinides, outermost electron enters in the 5f subshell whereas in lanthanides, outermost electron enters in 4f-subshell.
- Actinides have ability to form oxocations whereas lathanides do not have ability to form oxocations.
- The compounds formed by actinides are highly basic but the compounds formed by lanthanides are less basic.
- Actinides have greater tendency to form complexes with ligands such as thioether whereas lanthanides have less tendency to form complexes.
- Most of the actinide ions are colored whereas lanthanide ions are colorless.
- The paramagnetic nature of the actinides can be easily explained whereas this concept is very difficult to explain in case of lanthanides.
- 49Atomic and ionic size – As the atomic number increases, the atomic size increases and effective nuclear charge also increases which attracts the outermost shell more effectively. So, as we move left to right means from actinium to lawrencium in the actinide series, there is gradual decrease in the the…
- 48The f –block elements are those in which atoms or ions have valence electrons in f-orbital. They are also called inner transition elements because the last or valence electron enters in (n-2)f orbital means in anti-penultimate energy level. They are also referred as rare earth elements. The general electronic configuration…
- 42Atomic and ionic size – We all know that, the atomic size increase with increase in atomic number due to addition of new shell but in lanthanide series, as we move from left to right (cerium to lutetium), the atomic and ionic size decrease with increase in atomic number. The…
- 42Lanthanides are used as catalyst to speed up the chemical reactions. It is widely used in peteroleum or refining industry for conversion of crude oil into consumer products –gasoline, kerosene, heating oil etc. They are strong reducing agents. They are used in streetlights, searchlights, optical lenses. Lanthanides oxide are used…
- 41In lanthanides series, first few elements are quite reactive with calcium but with increase in atomic number, their reactivity is quite similar to aluminum. Lanthanides when reacted with carbon in inert atmosphere, then there is the formation of carbides.On gentle heating, it combine with hydrogen. Lanthanides form halides in the…