The solid sink to the bottom when placed in a container of water. what does this tell you about it's density

That the total density of the solid is more then the water

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.

Thermohaline circulation and gyres