Which of the following is the best example of physical weathering?
a. sediment piling up at the mouth of a river b.
plant roots growing through concrete and splitting it c.
waves carrying sand away from a beach d.
small rocks being carried along a river bed

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.