Identify the ferromagnetic element from the following.

$A$ substance which is not paramagnetic is

Cerium $(IV)$ has a noble gas configuration. Which of the following is the correct statement about it?

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.

Number of unpaired electrons in $Mn^{4+}$ is

Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points:
$(i)$ electronic configurations,
$(ii)$ oxidation states,
$(iii)$ ionisation enthalpies,and
$(iv)$ atomic sizes.