What is the highest oxidation state exhibited by any transition element among all?

Predict which of the following will be coloured in aqueous solution: $Ti^{3+}, V^{3+}, Cu^{+}, Sc^{3+}, Mn^{2+}, Fe^{3+},$ and $Co^{2+}$. Give reasons for each.

Platinum, Palladium and Iridium are called noble metals because

In which of the following ions is $d-d$ transition not possible?

The pair of ions with paramagnetic nature and same number of electrons is

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ Transition elements contain $d$-orbitals.
$(b)$ Ions of transition elements contain incompletely filled $d$-orbitals.
$(c)$ Only elements with completely filled $3d$ orbitals are considered transition elements.
$(d)$ Only elements that have incompletely filled $d$-orbitals in their ground state as well as in their ions are called transition elements.