CLUE Curriculum Name: Florida International University PID: Worksheet 2.4 Spectroscopy BE SURE TO INCLUDE ALL WORK AND UNITS! 1. The emission spectrum for helium is given below a. Draw energy diagrams to help you construct a step-by-step description for the processes involved in the production of an emission spectrum. Be sure to include both the processes by which energy is absorbed and emitted. b. Draw an energy diagram to compare the possible electron transitions that would produce the red emission line at the left of the spectrum and the blue line at the far right of the diagram. Red Yellow Blue
CLUE Curriculum Name: Florida International University PID: c. Explain why we use energy diagrams to illustrate electron transitions, rather than using a Bohr model of the atom. 2a. You can calculate the deBroglie wavelength of any object from the equation λ = h/mv. If you are given the mass in kg and the velocity in m/s, using the fact that 1J = 1kg.m 2 /s 2 , show what units you would get for λ. b. The mass of a neutron is 1.6749 x 10 -27 kg. How fast would it have to travel to be diffracted by a sheet of aluminum foil (the spacing between Al atoms in aluminum foil is about 300 pm) c. If we had a 145 g baseball what speed would the baseball have to move at to have the same wavelength as the neutron above?
CLUE Curriculum Name: Florida International University PID: Helpful Equations and Constants: E = h n c = l n h = 6.626 ´ 10 - 34 J s c = 3.0 ´ 10 8 m s 1J = 1kg.m 2 /s 2 1 pm = 1 x 10 – 12 m