n 1  :  CONSERVATION OF ENERGY - called also first law of thermodynamics   2  :  a law in physics: mechanical work can be derived from the heat in a body only when the body is able to communicate with another at a lower temperature or all actual spontaneous processes result in an increase of total entropy - called also second law of thermodynamics   3  :  a law in physics: at the absolute zero of temperature the entropy of any pure crystalline substance is zero and its derivative with respect to temperature is zero - called also third law of thermodynamics  .
 
 
 
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