1. According to the classical theory of physics, the energy radiated by a blackbody approaches infinity as the wavelength of the emitted light approaches zero.

a. Why was this considered a problem for classical physics?

b. Max Planck solved this problem in 1900. What was the key to the solution?

c. How does Planck's assumption solve the "ultraviolet catastrophe"?

2. A ringing bell oscillates at 440 Hz.

a. How much energy (in joules) is carried away in a one-quantum change of this system?

b. Convert your answer to units of electron-volts.

3. The equation for the maximum kinetic energy of an ejected photo¬electron is ICE,ax= hf - hft.

a. Rearrange this equation to solve for the work function.

b. If photoelectrons with 2.55 eV of maximum kinetic energy are observed when a 1.17 x 1015 Hz light is used, find the work function of the metal.

4. Write a brief description of Rutherford's model of the atom.

5. Why was Rutherford surprised that some of the alpha particles were Scattered backwards?

6. Even though some atoms were scattered backwards, why did Rutherford conclude that the atom was mostly empty space?

7. A major problem with Rutherford's model is that atoms would 'quickly collapse rather than continue to exist (as we know from observation of the everyday world). Eiplain in terms of energy why the Rutherford atom would collapse.