Question

Which of the following elements belongs to first inner transition series?

Options

• Pu

• Pr

• Bk

• Fm

Answer 1

Pr

Explanation:

The element praseodymium (Pr) belongs to the first inner transition series. The elements in this series range from cerium (atomic number 58) through lutetium (Lu, atomic number 71). Because the chemistry of each element closely matches that of lanthanum, these elements are known as lanthanoids.