Explain the physical properties of group $14$ elements.

(N/A) Electronic Configuration: The valence shell electronic configuration of these elements is $ns^{2} np^{2}$.
Covalent Radius: There is a considerable increase in covalent radius from $C$ to $Si$,thereafter from $Si$ to $Pb$ a small increase in radius is observed. This is due to the presence of completely filled $d$ and $f$ orbitals in heavier members.
Ionization Enthalpy: The first ionization enthalpy of group $14$ members is higher than the corresponding members of group $13$. The influence of inner core electrons is visible here also. In general,the ionization enthalpy decreases down the group. $A$ small decrease in $\Delta_{i}H$ from $Si$ to $Ge$ to $Sn$ and a slight increase in $\Delta_{i}H$ from $Sn$ to $Pb$ is the consequence of the poor shielding effect of intervening $d$ and $f$ orbitals and the increase in the size of the atom.
Electronegativity: Due to their small size,the elements of this group are slightly more electronegative than group $13$ elements. The electronegativity values for elements from $Si$ to $Pb$ are almost the same.