When you add food coloring to water, is a chemical or physical change?

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.

Which of these features are formed when hot groundwater is forced out through cracks in the earth's surface?

Air can be considered a mixture. which statement does not explain why?