What are $d$-block elements and transition elements? Explain characteristics of $d$-block elements.

(N/A) -block elements are elements belonging to groups $3$ to $12$ in the periodic table,where the last electron enters the $(n-1)d$ orbital. Their general electronic configuration is $(n-1)d^{1-10}ns^{0-2}$.
Transition elements are defined as elements that have partially filled $d$-orbitals in their ground state or in any of their common oxidation states. Thus,$Zn$,$Cd$,and $Hg$ (having $d^{10}$ configuration) are $d$-block elements but not transition elements.
Characteristics of $d$-block elements:
$1$. They are all metals with high melting and boiling points.
$2$. They exhibit variable oxidation states.
$3$. They form coloured ions and compounds.
$4$. They show paramagnetic behaviour due to the presence of unpaired electrons.
$5$. They act as good catalysts due to their ability to adopt multiple oxidation states and provide a large surface area.