Hard water contains calcium and magnesium, which undergo oxidation and
clog water pipes. which statement best describes this change as a chemical change?
a. calcium and magnesium dissolve in water.
b. calcium and magnesium evaporate on contact with the walls of the pipe.
c. calcium and magnesium form precipitates of their respective oxides.

According to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? view available hint(s) according to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? trigonal bipyramidal tetrahedral square planar determination of electron geometry requires information on whether the electron groups are lone pairs or bonding groups.