Answer
The order of decreasing number of unpaired electrons is:
Cr > Fe > Mn$^{4+}$ > Ti$^{2+}$ > Cu$^{2+}$ > Sc$^{3+}$
Work Step by Step
The order of decreasing number of unpaired electrons is:
Cr > Fe > Mn$^{4+}$ > Ti$^{2+}$ > Cu$^{2+}$ > Sc$^{3+}$