Question: State the hybridization used and the molecular geometry shape of hydroxide ion, OH-. Okay, so I draw out the Lewis structure, where there are 6 electrons (3 lone pairs) around the O atom, which is bonded to the H atom. So, I think base on the 3 nonbonding domains and 1 bonding domain, I think the shape is tetrahedral, but it seems weird to me, because I think it may be linear. Then, regarding the hybridization, I think the O atom uses sp3 hybridization, but then again, I think there is no hybridization involved, because O can use the remaining empty 2s orbital to bond to the only one electron from H atom. Which one is the correct one?