Question

PC8.Q1 014] A photon with wavelength 0.120 nm scatters off an electron that is initially at rest. The speed of the recoiling, non-relativistic electron is 7.00x106 m/s immediately after the collision. a) Name this process and explain its significance for the b) Calculate the energy of the incoming photon and the c) Based on energy conservation calculate the energy of development of modern physics. [1] momentum of the recoiling electron. [2] the outgoing (scattered) photon and its wavelength. [31

Answer 1

lambda = 0.120 nm , speed of electron = 7 times 10^6 m/s a) it is the process of photo electric effect b) energy of incoming photon = hc /lambda = 6.63 times 10^-34 times 3 times 10^8 / 0.120 times 10^-9 = 1.6575 times 10^-15 joule momentum of electron = 9.1 times 10^-31 times 7 times 10^6 = 6.37 times 10^-24 NS c) energy of incoming photon = energy of outgoing photon + energy of electron 1.6575 times 10^-15 = E' + 1 // 2 times 9.1 times 10^-31 times (7 times 10^6 )^2 1.6575 times 10^-15 - 2.2 95 times 10^-17 = E ' E' = 1.635205 times 10^-15 J let lambda' be the wavelength of outgoing photon E ' = hc /lambda ' lambda' = 6.63 times 10^-34 times 3 times 10^8 /1.635205 times 10^-15 = 1.2 1636 times 10^- 10 m lambda' = 0.121636 nm