Question

Choose the incorrect statement among the following:

• A. All the actinoid elements are radioactive.
• B. Alkali and alkaline earth metals are s-block elements.
• C. Chalcogens and halogens are p-block elements.
• D. The first member of the lanthanoid series is lanthanum.

Answer 1

Answer: (D)

Lanthanoids are $\_{58}^{}Ce-_{71}Lu$ ( $14$ elements ).
Electronic configuration of $_{\text{57}} \text{La} = \left[\text{Xe}\right] \text{6s}^{2} \text{5d}^{1}$ and it is a d-block element.