To calculate the partition function for a system of 300 molecules occupying an energy level of 10 J at a temperature of 300 K using the classical harmonic oscillator model, we need to use the Boltzmann factor and the partition function formula.The Boltzmann factor is given by:Boltzmann factor = e^-E / kT where E is the energy level, k is the Boltzmann constant 1.38 x 10^-23 J/K , and T is the temperature.For this problem, E = 10 J, k = 1.38 x 10^-23 J/K, and T = 300 K.Boltzmann factor = e^-10 / 1.38 x 10^-23 x 300 Now, we need to calculate the partition function, which is given by:Partition function q = [e^-E / kT ]Since we have 300 molecules, we need to sum the Boltzmann factors for each molecule. However, since all molecules have the same energy level and temperature, the Boltzmann factor will be the same for each molecule. Therefore, the partition function can be simplified as:q = 300 * Boltzmann factorq = 300 * e^-10 / 1.38 x 10^-23 x 300 Now, we can plug in the values and calculate the partition function:q = 300 * e^-10 / 4.14 x 10^-21 q 300 * e^-2.42 x 10^20 The partition function is a very large number, which is expected for a system of 300 molecules. The partition function gives us information about the distribution of molecules among different energy levels and can be used to calculate thermodynamic properties of the system.