Solid metals can be modeled as a set of uncoupled harmonic oscillators of the same frequency with energy levels given by En = hwn = 0, 1, 2, ... where the zero-point energy (the lowest energy state) of each oscillator has been adjusted to zero for simplicity. In this model, the harmonic oscillators represent the motions of the metal atoms relative to one another. The frequency of these oscillators is low so that ✪ n = ħw KB and the system vibrational partition function is given by 3N = = 224 1 (1 - e O/T (a) If the system contains one mole of atoms, find the average energy (in J) of this system at Ⓒ T= 172 K. (You can use = = pkB.) T (b) What is the absolute entropy (in J/K) for this system? You can use either the Gibbs expression for S, or the system partition function to make this evaluation (they are equivalent, as your reading assignment indicates).

A quantum system is described by a wave function (r) being a superposition of two states with different energies E1 and E2: (x) = c191(r)e iEit/h+ c292(x)e¯iE2t/h. where ci = 2icz and the real functions p1(x) and p2(r) have the following properties: vile)dz = ile)dz = 1, "0 = rp(x)T#(x)l& p1(x)92(x)dx% D0. Calculate: 1. Probabilities of measurement of energies E1 and E2 2. Expectation valuc of cnergy (E)

An electron moving in a box of length ‘a’. If Z1 is the wave function at x1 = a/4 with n=1 and Z2 at x = a/4 for n=2 find Z1/Z2

An electron is trapped in an infinitely deep one-dimensional well of width 0,251 nm. Initially the electron occupies the n=4 state. Suppose the electron jumps to the ground state with the accompanying emission of photon. What is the energy of the photon?