Why are lanthanides and actinides are placed separately in the modern periodic table ?
Answers
Because both lanthanides and acitinides feature the filling of f−orbitals, which as valence electrons, give rise to some peculiar chemistry.
Explanation:
Just as the filling and partial filling of the d−orbitals gives rise to a distinct transition metal chemistry, the filling of the f−block gives valence orbitals that are extremely diffuse and multi-lobed. f−orbitals shield the nuclear charge VERY imperfectly. f−block metals are thus highly Lewis-acidic, and they tend to form M3+ ions (though other oxidation states are known). The similar chemistry across the 2 periods is sufficient to warrant grouping these lanthanides and actinides together.
Answer: since lanthanides and actinides have completely different properties than the rest of the elements of periodic table they cannot be placed with the other elements lanthanides are similar to grup 2 elements but actinides are all radioactive elements
Explanation: