There are four series in the block: 3d 4d 5d and 64d .
The series is incomplete, whereas the 3d 4d and 4d series each include ten elements.
The d-subshell has five orbitals, each of which can hold two electrons.
As a result, each of the three series has ten elements.
Final Answer :
The diffusing electron goes into the (n-1)d-subshell. The d-subshell can hold up to ten electrons at a time.