Does a rock have a freezing point?

Answer 1

To a large extent, rock is already frozen. There are 5 states of matter: * Plasma * Gas * Liquid * Liquid Crytal * Solid Liquid crystal only applies to certain highly specialised compounds, although there is some evidence that all of them experience this stage in a very narrow band between solid and liquid, but that this band is so narrow that it's almost impossible to attain without it going beyond. Plasma is a gas so highly heated that all molecules break down and the electrons disasociate - they are no longer bound to their atoms. This leaves Solid, Liquid and Gas. If you view the following image: http://www.geocities.com/paul_j_hurley@btinternet.com/education_items/images/ water_states.jpg edit: it keeps on doing this! the above should all be 1 line! This is a diagram of the normal states of matter for water. If you cross reference the temperature with the pressure, you will get the relevant state. I've drawn a blue ine on the diagram for a pressure of 1 atmosphere. as you go up this line (rising temperature) then at 0 degrees centigrade you move from the solid area to the liquid area and at 100 degrees into the gas area. This also explains why at lower pressures (such as up a mountain) water boils at a lower temperature (move the blue line to the left). Where the 2 red lines meet is called the triple point. If you now view the following diagram: http://www.geocities.com/paul_j_hurley@btinternet.com/education_items/images/ 2-state.jpg Edit: and again. I've put water (red line) and another compound (green line) on the same diagram You will note they are both the same shape, but the triple points are in vastly different places, according to the chemical properties of these compounds. So, for a temperature and pressure at the blue cross, water is a liquid and the other substance (such as rock) is a solid. I.e. rock is already a frozen solid at this temperature. You will also note that to the left of the triple point, it goes straight from a solid to a gas. This is called sublimation. Depending on where the triple point of the substance is, all compounds sublime below this. Water will sublime below approximately 0.006 atmospheres (it's triple point is at this pressure), wheras carbon dioxide has it's triple point at 5.2 atmospheres. This why carbon dioxide 'dry ice' has no liquid form (the pressure ON EARTH is too low), while on Mars, with an atmospheric pressure of 0.005 atmospheres, liquid water cannot form (although it can form both a gas and a solid - believe it or not it can snow on mars, but not rain.)

Answer 2

No, rocks do not have a freezing point like liquids. Rocks are solid and do not change from a solid to a liquid state based on temperature. However, some minerals within rocks may have specific melting points.