Question

how to fing number of unpaired electrons of ions of d block

Answer 1

Finding the number of unpaired electrons of transition metals is no different than finding the number of unpaired electrons of any other element. Same with electron configuration of d-orbitals. Once you've found the electron configuration of your atom/ion, find any incomplete orbitals (that is, find any s-orbitals that have less than two electrons, any p-orbitals that have less than six electrons, or any d-orbitals that have less than ten electrons), if any. For each unfilled set of orbitals, place however many electrons you have in the orbitals, pairing them up only when you have no more empty orbitals. Then count how many orbitals have only one electron in it. Thus, if x is the number of electrons you have in this incomplete set of orbitals, then the number of unpaired electrons is x if x is less than or equal to 2l + 1, and 4l + 2 - x if x is greater than 2l + 1.

Yes, the neutral atoms of elements in group 2 have no unpaired electrons.