Which group of elements belongs to the f-block of the periodic table?

• A. Transition metals
• B. Lanthanides and actinides
• C. Alkali metals
• D. Halogens

Answer: (B)

Verified step by step guidance

1. Understand the layout of the periodic table, which is divided into blocks based on the electron subshell being filled: s-block, p-block, d-block, and f-block.
2. Recall that the f-block elements are characterized by the filling of the 4f and 5f orbitals, which correspond to the lanthanide and actinide series respectively.
3. Identify that transition metals belong to the d-block, alkali metals to the s-block, and halogens to the p-block, so these groups do not belong to the f-block.
4. Recognize that the lanthanides and actinides are the two series of elements that make up the f-block, located typically below the main body of the periodic table.
5. Conclude that the group of elements belonging to the f-block is the lanthanides and actinides.