Which of the following ins not an actionid?
(a) Curium (Z= 96)
(b) Californium (Z= 98)
(c) Uranium (Z = 92)
(d) Terbium (Z = 65)
Elements with atomic number Z = 90 to 103 are called actinoids. Thus, terbium (Z = 65) is not an actinoid. Terbium belong to lanthanoids.