Thallium, atomic number 81, possesses a unique valence electron configuration of [Xe]6s24f145d106p1. This extra valence electron allows thallium to exhibit variable oxidation states, primarily +1 and +3. Thallium(III) forms stable salts and compounds such as Tl(OH)3 and Tl3+. In contrast, thallium(I) compounds, including Tl2SO4, TlBr, and Tl2S, are less stable but showcase distinct chemical properties. Thallium’s emission and absorption spectra play a role in its industrial applications in semiconductor materials and electronic components.
