Question

Quantum Physics - Matter Waves 1 Matter Waves V i = (matter and photons), The Planck constant is 6.626x10^-34 J s. Case 1: An electron has a wavelength of 0.170 nm; 1nm = 10ºm. (a) Calculate the electron's momentum. Write the result in terms of 10-24 kg. m/s. Keep 3 decimal places. Enter a number x10-24g.m/s Submit (5 attempts remaining) (b) The mass of an electron is 9.11x10^-31 kg. Use the classical physics formula for momentum to calculate the speed of the electron. Write the result in terms of 106 m/s. Keep 2 decimal places. Enter a number x10m/s Submit (5 attempts remaining) (c) Use the classical physics formula for kinetic energy to calculate the kinetic energy of the electron. Write the result in terms of 10-19 Keep 2 decimal places. Enter a number J. *10-19 Submit (5 attempts remaining) Case 2 A neutron's mass is 1.67x10^-27 kg. Its kinetic energy is 0.16 eV. 1eV = 10-19). (d) Write this kinetic energy in terms of 10-19). Keep 3 decimal places. Enter a number x10-19 Submit (5 attempts remaining) (e) Calculate the neutron's momentum. Write the result in terms of 10-24 kg • m/s . Keep 3 decimal places. Enter a number x10-24kg. m/s Submit (5 attempts remaining) (1) Calculate the neutron's wavelength in nm, 1nm = 10-ºm. Keep 3 decimal places. Enter a number nm Submit (5 attempts remaining)

Answer 1

(a) P. h 24 3. 8981o 6.626x10934 0.120 X10-9 kg. m/ (6) mva 3.898 *10-24 -24 6 3.898 x 10 V- 4.278) x 10 m/s 9.11x10-31 (C) KE> 1 x 19.11860-31) x(4.278x100)? 6-19 83.381 x 10 J Case-2 (d) KE = 0.16 eV J -19 = 0.16 X 1-6x10 0.256 X 10-19 J (e) £mv ² 0.25081019 (6.252x1oys JX2 AVE 4 0.5537 X 10 m/s (1667 X10-27) 1.67X66??) (0.5837x10") p = mr -24 x 10 9.247 kg-m/s = da 6-62 6 8 10-34 rlo 6.71657 x 10 9.247 x 10-24 d=10.072 nm