The incorrect statement among the following is :

Question

Question

Actinoids are highly reactive metals, especially when finely divided.
Actinoid contraction is greater for element to element than Lanthanoid contraction.
Most of the trivalent Lanthanoid ions are colorless in the solid state.
Lanthanoids are good conductors of heat and electricity.

Answer 1

Explanation:

Actinoids: Actinoids are f-block elements starting from Th to Lr total of 14 elements. They are radioactive elements.

They are highly reactive metals especially when finely divided.
The 5f electrons of actinoids are poorly shielded as compared to the 4f electrons of lanthanoids. so effective nuclear charge on 5f electrons of the actinoids are more so actinoid contraction is greater.
Lanthanoids are inner transition metals having typical metallic structures and hence good conductors of heat and electricity.
Most of the trivalent lanthanoid ions are colored in a solid state due to the presence of f electrons.