Answer:
U
Explanation:
The first law of thermodynamics states that:
[tex]\Delta U = Q-W[/tex]
where
U is the internal energy of the gas, which represents the sum of the chemical and thermal energy stored in the atoms and molecules of the gas
[tex]\Delta U[/tex] represents the variation of internal energy
Q is the heat absorbed by the system
W is the work done by the system
So, the sum of the chemical and thermal energy stored in atoms and molecules is represented by U, the internal energy.
