Question

alpha poxticle cle approaches a ciole nucleu en comes to Sto at (74?, 118 n). Lt.th r9.23 tm befere returming alongts origmal poeth wag the alpha particles Kinetic ener

Answer 1

Given an alpha particle with 2 prolongs and 2 neutrons, [alpha = 2p, 2n] a gold nucleus with 79 protons and 118 neutrous, [A_u = 79p, 118n] distance of closer approach r_0 = 9.23 fm r_0 = 9.23 times 10^-15 as the alpha particle moves toward the gold nuleus its total kinetic energy is converted into electrostatic potential energy therefor kinefic energy = potential energy at of alpha.particles closest approach therefor k.E_alpha = 1 times 79 e times 2e/4 pi f_0 times r_0 [therefor u = 1/4 pi f_0 q_1 q_2/r] = 9 times 10^9 times 79 times 1.6 times 10^-19 times 2 times 1.6 times 10^-9/9.23 times 10^-15 rightarrow K.E_alpha = 3.94 timews 10^-12 joules