Why cant we use water in thermometers?
You could use water. It would work ok. But when it got to 4 centigrade it would start to expand and would not read true after that as water expands at that temperature. When it got to 100 centigrade it would boil and once again burst the thermometer. So yes it would work but only between 4 C and just below 100 C. Not alot of use as a thermometer then. When it froze at zero it would burst the thermometer. EDIT> Dear WASI. For your information It does not matter that water is a colourless transparent substance. So is alchohol but they make thermometers from it but they add RED die to it. Have you ever seen a thrmometer with a red line? Thats an alchohol thermometer. Also a water thermometer would need to be no bigger than an ordinary one. You are thinking of a water barometer.[that measures air pressure not temperature] That would need to be 10 meters high. A mercury ANEROID barometer need to be a meter high, and a water aneroid barometer needs to be 10.4 meters high, as that is air pres
