Quantum mechanics predicts that, at room temperature and ordinary pressures, an isolated atom in a gas cannot store any significant amount of energy except in the form of kinetic energy. Thus, heat capacity per mole is the same for all monatomic gases (such as the noble gases). More precisely, c V , m = 3 R / 2 ≈ ≈ 12.5 J ⋅ ⋅ K − − 1 ⋅ ⋅ m o l − − 1 and c P , m = 5 R / 2 ≈ ≈ 21 J ⋅ ⋅ K − − 1 ⋅ ⋅ m o l − − 1 , where R ≈ ≈ 8.31446 J ⋅ ⋅ K − − 1 ⋅ ⋅ m o l − − 1 is the ideal gas unit (which is the product of Boltzmann conversion constant from kelvin microscopic energy unit to the macroscopic energy unit joule, and the Avogadro number).