In SO2 sulfur dioxide , the central atom is sulfur S . To determine the hybridization of the central atom, we need to consider the number of electron domains around it. Electron domains include bonding pairs of electrons and lone pairs of electrons.Sulfur has 6 valence electrons, and oxygen has 6 valence electrons. In SO2, sulfur forms two double bonds with the two oxygen atoms. Each double bond consists of one sigma bond and one pi bond. So, sulfur has two sigma bonds and one lone pair of electrons.The number of electron domains around the central sulfur atom is 3 2 sigma bonds + 1 lone pair . According to the VSEPR Valence Shell Electron Pair Repulsion theory, these electron domains will arrange themselves in a trigonal planar geometry to minimize electron repulsion. To accommodate this geometry, the sulfur atom undergoes sp2 hybridization, which means it mixes one s orbital and two p orbitals to form three sp2 hybrid orbitals.In SO2, the sulfur atom's sp2 hybrid orbitals overlap with the oxygen atoms' p orbitals to form sigma bonds. The remaining unhybridized p orbital on the sulfur atom overlaps with the unhybridized p orbitals on the oxygen atoms to form pi bonds. This results in the formation of two double bonds one sigma and one pi bond each between the sulfur and oxygen atoms, creating the SO2 molecule with a bent molecular geometry due to the presence of the lone pair on the sulfur atom.