What is the total number of transition series of d-block elements?

Step-by-step solution

The d-block elements are distributed into four transition series based on the filling of d-orbitals: First transition series ( 3d series): Sc ( Z=21 ) to Zn ( Z=30 ) Second transition series ( 4d series): Y ( Z=39 ) to Cd ( Z=48 ) Third transition series ( 5d series): La ( Z=57 ), Hf ( Z=72 ) to Hg ( Z=80 ) Fourth transition series ( 6d series): Ac ( Z=89 ), Rf ( Z=104 ) to Cn ( Z=112 ) Therefore, there are a total of 4 transition series of d-block elements. Answer: 4