200cm³of 0.2M Na2SO4 are added to 200cm³ water are mixed well. The concentration of Na+ and SO4²- ​

What does the process of natural selection involve

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore

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.