generally from a solid to a gas.
Everything has a density
The density of chlorine at 0 0C and 760 mm col. Hg is 3,2 g/L; the density of air is 1,2 g/L.
inner core outter core mantle and crust
Because more dense has more pressure added to it and if you measered the density you could see that more dense things sink and less dense things float ontop of that water..