Question

Explain physical properties and oxidation states of $d$ block elements?

Answer 1

$d$- block elements

• From the third group of the modern periodic table to the twelfth group, there are elements known as $d$ block elements.
• $d$-block elements are those that can be found in Groups $3$ to $12$ of the periodic table.
• The common electron configuration is $(n-1)d^{1-10}n{s}^{1-2}$ .

Physical properties of $d$ block elements

• All transition elements, with the exception of mercury, which is a liquid, have a typical metallic structure and exhibit characteristics including conductivity, malleability and ductility, luster, high tensile strength, etc.
• The atomic radii decrease in a series as the atomic number increases, but the decrease is negligible at the midway.
• They have high enthalpies of hydration for their ions as well as high melting and boiling temperatures.
• Their initial ionization energies are greater than $s$-block elements' and lower than $p$-block elements', respectively.
• They are electropositive in nature.

Oxidation states of $d$ block elements

• Due to the high third ionization enthalpy value, $+2$ is the oxidation state of the $d$-block elements that is the most stable.
• The elements that exhibit a high number of oxidation states are found in the center of the series or very close to it.
• For example, Manganese $\left(\mathrm{Mn}\right)$ exhibits all oxidation states between $+2$ and $+7$.
• Due to partially filled $d$-orbitals, transition elements exhibit oxidation states that differ by a factor of unity.