How can you describe the state of equilibrium in a saturated solution that contains undissolved?

Acontrol during an experiment. might change remains constant does not exist does change

Can someone me with 3 and 4 plz. this is for masteries test.

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.