Question

Which of the following is not an actinide?

• A. Curium
• B. Californium
• C. Uranium
• D. Terbium

Answer 1

Answer: (D)

(i) Curium (At. no. $96$) belongs to actinide.
(ii) Californium (At. no. $98$) belongs to actinide.
(iii) Uranium (At. no. $92$) belongs to actinide.
(ii) Terbium (At. no. $65$) belongs to lanthanide series.
$\therefore$ Terbium is the correct answer.(i) Curium (At. no. $96$) belongs to actinide.
(ii) Californium (At. no. $98$) belongs to actinide.
(iii) Uranium (At. no. $92$) belongs to actinide.
(ii) Terbium (At. no. $65$) belongs to lanthanide series.