Q. Consider the following statements :
I. -block elements are found pure in nature.
II. -block elements form coloured ions, exhibit, variable valence and paramagnetism.
III. Lanthanoids contains the elements from
to
IV. Actinoids contains the elements from to .
Choose the option with all the correct statements :

 1038  145 Classification of Elements and Periodicity in Properties Report Error

Solution:

Statements II, III and IV are correct, while the statement I is incorrect.
It's correct form is as follows :
-block elements are never found in pure nature because of their high reactivity.