Elements which generally exhibit multiple oxidation states and whose ions are usually coloured are

Write down the electronic configuration of:
$(i) Cr^{3+}$
$(ii) Pm^{3+}$
$(iii) Cu^{+}$
$(iv) Ce^{4+}$
$(v) Co^{2+}$
$(vi) Lu^{2+}$
$(vii) Mn^{2+}$
$(viii) Th^{4+}$

Which of the following series of transition metal ions has a $3d^2$ electronic configuration?

What is the highest oxidation state of third row transition elements?

Which transition elements of the $3d$ series have an exceptional electronic configuration?

Which of the following general configurations of the outermost shell represents the chromium element [$Cr$'s atomic number $= 24$]?