Ch 29
44. In an atom, an electron has the following allowed energylevels, E1 = 1 eV, E2 = 4 eV and E3 = 6 eV. What are the observedemission and absorption wavelengths for this atom? Absorption:414.4 nm, 248.6 nm, Emission: 414.4 nm, 248.6 nm, 621.6 nm
45. In LASIK surgery, a laser is used to reshape the cornea ofthe eye to improve vision. The laser produces extremely shortpulses of light, each containing 1 mJ of energy. a) In each pulsethere are 9.7 x 1014 photons. What is the wavelength of the laser?192.9 nm b) Each pulse lasts only 20 nsec. What is the averagepower delivered to the eye during a pulse? 50kW
46. An electron with a speed of 4 x 106 m/s collides with anatom. The collision excites the atom from its ground state (1 eV)to a state with an energy of 8.9 eV. What is the speed of theelectron after the collision? 3.64 x 106 m/s
48. The absorption spectrum for an atom consists of thewavelengths 200 nm, 300 nm and 500 nm.
a) Draw the energy level diagram for this atom, labeling theenergy (in eV) for each level. The ground state energy level is at0 eV. E2 = 2.49 eV. E3 = 4.14 eV, E4 = 6.22 eV
b) What wavelengths are seen in the emission spectrum? 753.4 nm,333.3 nm, 597.7 nm
