State the first law of thermodynamics.

Explanation

The first law of thermodynamics, also known as the law of conservation of energy . States that "The total energy of an isolated system remains constant though it may change from to another."
The mathematical statement of the First Law is :
`DeltaU=q+w`
where q - the amount of heat supplied to the system w - work done on the system
w - work done on the system