In SO sulfur dioxide , the central atom is sulfur S . To determine its hybridization, we need to first find the number of valence electrons and the electron domains surrounding the central atom.Sulfur has 6 valence electrons, and each oxygen atom has 6 valence electrons. In SO, there is a double bond between sulfur and one oxygen atom, and a single bond between sulfur and the other oxygen atom. This accounts for 2 + 2 + 1 = 5 electron domains around the sulfur atom.Now, we can determine the hybridization based on the number of electron domains:- 2 electron domains: sp hybridization- 3 electron domains: sp hybridization- 4 electron domains: sp hybridization- 5 electron domains: spd hybridization- 6 electron domains: spd hybridizationSince there are 5 electron domains around the sulfur atom in SO, the hybridization of the central atom sulfur is spd.