Question 1209182
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Interesting fact from Science is that the volume of ice before melting  
is GREATER than the volume of the water after melting.


It is why the ice always floats on the surface of the water 
and does not sink in water.


Usually, school students learn this fact when they are 6th or 7th grade.


The difference in volumes is not so small.  The ratio of the ice density 
to the water density at normal conditions is about 0.92;
so the difference of volumes is about 8.7%.



Again, although the chemical formula of water in fluid state and in solid state 
is the same H2O, their phase states are different.


There is no any logical or physical reason to assume that their volumes 
before melting and after melting are the same.


We make this assumption with the only reason to solve the problem, 
but physically and logically we have no solid base for making this assumption.



                    Physically, this assumption is wrong.



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        Physically, at the phase change, the mass conserves, 

              but the volume does not necessary conserve.


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