How do f-block elements exhibit magnetic properties?

Here’s a explanation:

Magnetic properties of f-block elements

1. Cause of magnetism:
   • Magnetism comes from unpaired electrons in the f-orbitals.
   • The more unpaired electrons, the stronger the magnetic effect.
2. Lanthanides (4f elements):
   • Only 4f electrons contribute to magnetism because 4f orbitals are inside and shielded by outer electrons.
   • Magnetism mainly depends on number of unpaired 4f electrons.
3. Actinides (5f elements):
   • Both 5f and 6d electrons contribute because 5f orbitals are less shielded and more spread out.
   • Actinides often show stronger magnetism than lanthanides.
4. Types of magnetism:
   • Paramagnetic: Most f-block elements with unpaired electrons.
   • Diamagnetic: Only if all f-electrons are paired (rare).

In short:

• Magnetism comes from unpaired f-electrons.
• Lanthanides → weaker magnetism, 5f electrons are hidden.
• Actinides → stronger magnetism, 5f electrons less hidden.