Question

The last element of lanthanide series is:
A. Lawrencium
B. Lutetium
C. Cerium
D. Thorium

Answer 1

Hint: The series in which elements are present in between cerium ($Ce$ , atomic no. 58) and lutetium ($Lu$ , atomic no. 71) is commonly known as the lanthanide series. It is also termed as transition elements.

Step by step answer: The lanthanides and actinides are located mostly in the "f-block" of the periodic table. The lanthanides are a group of 15 elements of atomic numbers from 58 (cerium$Ce$) through 71(Lutetium$Lu$) in which scandium (atomic number 21) and yttrium (atomic number 39) are sometimes included. So from this we come to know that lutetium is the last element of lanthanide series.

So the correct option must be B.

Additional Information: Lanthanides are used in products such as hybrid cars, superconductors, and permanent magnets. Lanthanides are highly reactive with elements from the halogen group.

Note: One important inference that we can take from lanthanide series is that all of the lanthanides have at least one stable isotope except for promethium. Lanthanides are mostly present in the f block of periodic table.