Ionisation Energies and electron affinity
The following represents the electronic configuration and its associated term symbol for the ground state neutral gaseous atom. The configuration associated with iron in its compounds is not necessarily the same.
Iron's "busy" spectrum is a natural, irregular wavelength scale with which to calibrate spectrographs and help assign unknown spectral lines.
WebElements now has a WebElements shop at which you can buy periodic table posters, mugs, T-shirts, games, molecular models, and more.