First draw the electron structure of propane and use the VSEPR theory to explain the geometry and hybridization around each carbon atom.
In propane, there are three carbon atoms connected in a straight chain and eight hydrogen atoms are connected to carbon atoms. Three hydrogen atoms are joined to each terminal carbon and two hydrogen atoms are joined to each middle carbon atom.
Each carbon atom in propane has four charge clouds (four single bonds). So, each carbon has a tetrahedral geometry which implies that each carbon is sp³ hybridized.
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