Question

Which is more stable ${\mathrm{Fe}}^{2+}$or ${\mathrm{Fe}}^{3+}$?

Answer 1

1. ${\mathrm{Fe}}^{2+}$or ${\mathrm{Fe}}^{3+}$ both are chemical elements and are derived from Iron.
2. The number of valence shell electrons decides the stability of an atom.
3. The fully filled atom is said to be stable.
4. The atomic number of Iron is $26$ and the electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^6$.
5. By losing 2 electrons it forms ${\mathrm{Fe}}^{2+}$ and so the electronic configuration becomes $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^6$.
6. Similarly, by the loss of three electrons it forms ${\mathrm{Fe}}^{3+}$ and the electronic configuration becomes $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^5$.
7. Thus, by losing three electrons from Iron attains a positive charge on it.
8. After fully filled electronic configuration, half-filled configuration is much more stable compared to other electronic configurations.
9. Therefore, ${\mathrm{Fe}}^{3+}$ is more stable than ${\mathrm{Fe}}^{2+}$.