Identify the element having highest enthalpy of atomization from following.
Identify the element having highest enthalpy of atomization from following.
$\operatorname{Cu}(Z=29)$
$\mathrm{Fe}(Z=26)$
$Zn(Z=30)$
$\mathrm{Sc}(Z=21)$
Solution
Fe $(Z=26)$
The atomisation enthalpy of iron (Fe) is the highest. It is determined by the strength of the metallic connection, which is in turn determined by the amount of unpaired electrons. The metallic link will be stronger as the number of unpaired electrons increases. In the electronic configuration of $\mathrm{Fe}(Z=26)$, four unpaired electrons are present.
$\mathrm{Fe}=1 \mathrm{~s}^{2}, 2 \mathrm{~s}^{2}, 2 \mathrm{p}^{6}, 3 \mathrm{~s}^{2}, 3 \mathrm{p}^{6}, 3 \mathrm{~d}^{6}, 4 \mathrm{~s}^{2}$
Number of unpaired electrons $=4$
Number of unpaired electrons $=4$