Question
Chemistry Question on d -and f -Block Elements
Which among the following is an actinoid element?
A
Pa
B
Lu
C
Gd
D
Pr
Answer
Pa
Explanation
Solution
An actinoid element belongs to the actinide series, which is the series of elements in the periodic table with atomic numbers from 89 to 103. Based on this information, we can determine which of the following elements is an actinoid element:
(A) Pa (Z=91) is an actinoid element.
(B) Lu (Z=71) is a lanthanoid (also known as lanthanide) element, not an actinoid element.
(C) Gd (Z=64) is a lanthanoid element, not an actinoid element.
(D) Pr (Z=59) is a lanthanoid element, not an actinoid element.
Therefore, the only actinoid element among the options is: (A) Pa (Z=91)