The population density, N₁, corresponding to a discrete energy level, E₁, for a group of N like particles in Local Thermodynamic Equilibrium (LTE) state can be described by the following equation N₂ 9₂c-Ex/(KRT) Z(T) i) Define the remaining quantities or constants in the above equation. ii) Produce an expression for Z(T) as a function of T. In order to calculate Z(T) for a particular atomic gas such as argon, what atomic data or information needs to be made available before the calculation is carried out? To uniquely describe the population density distribution corresponding to different discrete energy levels of a diatomic molecular gas such as CO in equilibrium, how many Z(T) functions need to be used and why?

The population density, N₁, corresponding to a discrete energy level, E₁, for a group of N like particles in Local Thermodynamic Equilibrium (LTE) state can be described by the following equation N₂ 9₂c-Ex/(KRT) Z(T) i) Define the remaining quantities or constants in the above equation. ii) Produce an expression for Z(T) as a function of T. In order to calculate Z(T) for a particular atomic gas such as argon, what atomic data or information needs to be made available before the calculation is carried out? To uniquely describe the population density distribution corresponding to different discrete energy levels of a diatomic molecular gas such as CO in equilibrium, how many Z(T) functions need to be used and why?