When sand is coated with a layer of trimethylhydroxysilane, (CH3)3SiOH, it repels water and can no longer get wet. Hydrophobic sand (aka, magic sand) is fun to play with, but it can also have useful applications in agriculture to reduce water consumption (Water Resour. Manag. 2010, 24, 2237–2246). Predict the geometry for the silicon atom in trimethylhydroxysilane. The geometry of the silicon atom in trimethylhydroxysilane is: