The source applies the idea of macrostates and microstates to a real gas sample. How many atoms does it say are present in just 1.0 cm^3 of an ideal gas at 1.0 atm and 0°C?

1. The source points out that even a very small sample of gas contains an enormous number of atoms, each contributing to the gas's microstates. 2. It gives a specific figure for this: 1.0 cm^3 of an ideal gas at 1.0 atm and 0°C has 2.7 x 10^19 atoms. 3. Because each of these atoms can occupy many possible positions and velocities, this huge atom count is why even one macrostate of the gas corresponds to an immense number of microstates. 4. Option C's figure of 1.0 x 10^23 is close to a mole's worth of atoms but is not the number given for this particular 1.0 cm^3 sample. 5. Options A and B do not match the leading digits and exponent given for this sample, so neither reflects the stated figure. _Source: OpenStax College Physics (CC BY 4.0), Ch 15 "Thermodynamics", section 15.7 Statistical Interpretation of Entropy and the Second Law of Thermodynamics: The Underlying Explanation_