Thermal Energy Calculator

Find the thermal energy of an ideal monatomic gas.

Thermal energy (J) 3,741.51

Formula: U = (3/2)·n·R·T

Step-by-step with your numbers:

1. Values used:

2. Amount = 1 mol

3. Temperature = 300 K

5. Thermal energy = 3,741.51J

Did we solve your problem today?

The thermal (internal) energy of an ideal monatomic gas comes from its molecular motion.

The math behind it

U = (3/2)·n·R·T. Each degree of freedom contributes ½kT per molecule.

1 mol at 300 K → about 3742 J.

What about diatomic gases?

They have more degrees of freedom: U = (5/2)nRT at room temperature.