State the first law of thermodynamics. Explain its mathematical notation.

Explanation

First law of thermodynamics :
The law of conservation of energy is taken as the first law of thermodynamics.
Statements :
(i) "Energy can neither be created nor destoyed, although it can be transformed from one form to another
(ii) It is impossible to construct perpetual motion machine of first kind".
(iii) The total energy of the system and surroundings.in constant".