State the first law of thermodynamic?

The first law of thermodynamics, also known as the law of energy conservation, states that energy cannot be created or destroyed in an isolated system. The total amount of energy in a closed system remains constant, although it can be converted from one form to another (such as from heat to work or vice versa) or transferred between different parts of the system. In simple terms, the first law of thermodynamics asserts that energy is conserved in any thermodynamic process.