Name: Physics B Module 12 Homework Directions: Complete the following problems showing all of your work. Turn in your completed worksheet to your teacher. e 4 Short Answer 1. Explain the historical development of the atomic model from Democritus to Bohr. 2. What is the difference between an emission spectrum and an absorption spectrum for a specific element? 3. What does it mean to say something is radioactive? Go on to the next page 4, How do nuclear reactors work? 5. What are the postulates for the Special Theory of Relativity? Practice 6. The color orange has a wavelength of 630 nm. What is the energy of an orange photon in eV? Go on to the next page The energy levels for a Bohr atom are shown below. Use this diagram to solve problems 7 and 8. N OeV -2.5eV -4.0eV -7.0eV -12.5eV 7. What amount of energy is needed for an electron to jump fromn=1ton =4? 8. What is the wavelength of the photon needed to make this happen? Is it emission or absorption? 9. If the atomic mass of Sodium-18 is 18.02597 u, what is the binding energy? Go on to the next page 10. Complete each of the following radioactive decay equations. 235 U - Th + 4a 87sr te DC - 1B+ He 11. The half-life of Uranium-237 is 5.83 x 105 seconds. What is the decay constant? 12. The half-life of Uranium-237 is 5.83 x 105 seconds. If you have a sample with 5.89 x 1024 atoms in it, how much of that sample is left after 1.75 x 10 seconds? -Go on to the next page-Application 13. How can scientists know the age of an artifact they pull from a historical dig? 14. Why do doctors place a sheet of lead over your body when you have x-rays done? Would the same be held true for gamma rays? 15. A friend is adamantly against building any more nuclear power plants in your local area. You, however, understand its benefits. How might you address your friend to convince him of the need for the new power facility