Lanthanoids and Actinoids 👩‍🔬

 Lanthanoids: 

* Properties of lanthanoids: 

1. Soft metals with silvery white colour and moderate densities of ~7g/cm³. Colourand brightness reduces on exposure to air.
2. Good conductor of heat and electricity. 
3. Except promethium(Pm), all are non radioactive in nature. 
4. The atomic and ionic radii decreases from lanthanum(La) to lutetium(Lu). This is know as lanthanoid contraction.
5. Binding to water is common(i.e.) such that H2O is often in products when isolated from aqueous solution.
6. Coordination number usually are greater than 6, typically 8,9.....(upto 12 found).
7. The lanthanoids are strongly paramagnetic. Gadolinium becomes ferromagnetic below 16°C. The other heavier lanthanoids terbium, dysprosium, holmium, erbium, thulium, and ytterbium becomes ferromagnetic at much lower temperatures.
8. Magnetic and optical properties are largely independent of environment.

Applications of lanthanoids:

1. It is inside the colour telivision tubes.
2. The most notable application is the Nd:YAG laser.
3. Erbium-doped fibre amplifiers are significant devices in the optical fiber communication system
4. Lanthanoids are used in hybrid cars, superconductors and parmanent magnets.

* Actinoids:

Properties of Actinoids :

1. Similar to lanthanoids, they appear silvery white in clour.
2. These are highly reactive radioactive elements.
3. They experience decrease in the atomic and ionic radii from Actinoids (Ac) to lawrencium(Lw) , known as Actinoid contraction.
4.  They usually exhibit +3 oxidation state. Elements of first half of the series usually exhibit higher oxidation state.

*Application of Actinoids:

1. ThO2 with 1% CeO2 was used as a major source of indoor lighting before incandescent lamps came into existence only because of these oxides convert heat energy from burning natural gas to an intense light. 
2. Even today, there is a great demand for ligths for outdoor camping. 

* Similarities between lanthanoids and Actinoids:

1. Both the series show a +3 oxidation state.
2. In both the series, f-orbitals are filled gradually. 
3. Ionic radius of the elements in both series decreases with an increase in atomic number. 
4. The electronegativity of all the elements in both the series is low and are said to be highly reactive. 
5. The nitrates, perchlorates and sulphates of all the elements are soluble while the hydroxides, fluorides and carbonates are insoluble. 

* Difference between Lanthanoids and Actinoids :

1. Lanthanoids show a maximum oxidation state of +4 while Actinoids show oxidation state of +3,+4,+5,+6 and +7.
2. Lanthanoids do not form complexs easily.  Actinoids have a great tendency to form complexs with ligands such as thio- ethers.
3. All lanthanoids are  non- radioactive except promethium but Actinoids  are radioactive in nature. 
4. Lanthanoids do not form oxocations, but actinoids form oxocations such as UO+, PuO+, NpO2+.
5. Most of the lanthanoids are colourless in nature wheras the actinoids are colored inons     

# Electronic configuration. 👈🥰