What are the lanthanide series? How many elements are there in the lanthanide series?

 Lanthanide Series: Definition and Elements

What is the Lanthanide Series?

The lanthanide series consists of a group of 15 metallic elements in the periodic table, ranging from lanthanum (La, atomic number 57) to lutetium (Lu, atomic number 71). These elements belong to the f-block and are also known as rare earth elements.

How Many Elements Are in the Lanthanide Series?

The lanthanide series contains 15 elements, which are:

1. Lanthanum (La) - 57
2. Cerium (Ce) - 58
3. Praseodymium (Pr) - 59
4. Neodymium (Nd) - 60
5. Promethium (Pm) - 61 (radioactive, no stable isotope)
6. Samarium (Sm) - 62
7. Europium (Eu) - 63
8. Gadolinium (Gd) - 64
9. Terbium (Tb) - 65
10. Dysprosium (Dy) - 66
11. Holmium (Ho) - 67
12. Erbium (Er) - 68
13. Thulium (Tm) - 69
14. Ytterbium (Yb) - 70
15. Lutetium (Lu) - 71

Key Features of Lanthanides:

• All have a +3 oxidation state as their most common oxidation state.
• They are soft, silvery-white metals that tarnish easily in air.
• Their 4f orbitals are progressively filled across the series.
• They exhibit the lanthanide contraction, leading to decreasing atomic and ionic radii.
• They are widely used in magnets, phosphors, catalysts, and electronic devices.