Which of the following is not an actinoid?

Question

Which of the following is not an actinoid? (A) Curium (Z = 96) (B) Californium (Z = 98) (C) Uranium (Z = 92) (D) Terbium (Z = 65)

Tardigrade Admin · Accepted Answer

Terbium (Z=65) is a lanthanoid and all others are actinoids. Lanthanoids have atomic numbers from 58 to 71 . Actinoids have atomic numbers from 90 to 103 .

Q. Which of the following is not an actinoid?

Curium (Z = 96)

Californium (Z = 98)

Uranium (Z = 92)

Terbium (Z = 65)

Terbium $(Z = 65)$ is a lanthanoid and all others are actinoids. Lanthanoids have atomic numbers from $58$ to $71$ . Actinoids have atomic numbers from $90$ to $103$ .