Question

Activity 27-5. Nuclear fusion [Accompanies Section 27-5] In one fusion reaction that occurs in the cores of certain stars, a nucleus of helium-4 (-He, with two protons and two neutrons) fuses with a nucleus of neon-20 (2°Ne, with 10 protons and 10 neutron) to form a nucleus of magnesium-24 (24Mg, with 12 protons and 12 neutrons). A gamma-ray photon (y) is also produced: He + 20Ne + 24 Mg + y (a) Rank the following nuclei in order of their binding energy per nucleon, from largest to smallest. If any two nuclei have the same binding energy per nucleon, state this. Explain how you made your ranking; (i) The helium-4 (235U) nucleus (ii) The neon-20 (134Te) nucleus (iii) The magnesium-24 (9PZr) nucleus — Activity 27-5 [continued]. (b) Using your results from part (a), explain why energy is released in the fusion of “He and 20Ne. (c) In the neutron-induced fission of uranium-235 (235U), the neutron that triggers the reaction can be moving very slowly relative to the 235U nucleus before they collide, with almost zero kinetic energy. But in order for the fusion of “He and 20Ne to take place, the “He nucleus must be moving very rapidly relative to the 20Ne nucleus before they collide. Explain why there is a difference.

Answer 1

Ne 8.134ourent stable (a) we know from chart Binding energy per nucleon for He "-7.40526 reuz) Stable lince is i magic - 7.59 Mv Is Not table. numbered 1235 nuclei Te 134 Mgay Zraq to stablest lyt lies in teeble region of B.E curve 8.41457 Mev) Norntable. -). Stablest (as ir lies in stable region of B. E curve) 3) The nuclear energy [wheather is i nuclear fusion hission) is due to conversion of man into energy, There will be man defect that exists between products & Sum which itself is released in form of heat energy in accordence with Einstein man energy relation (E=mc²) eft is direct proof for Conversion of man un to energy. (e) In case of fission, we prefer thermal neubon (slow moving neutrons) are made to hit the uranium necem as order to carryout nuclear filmen rechin. Here there will be no force of repulsion between neuson and uranium nuchi, where as in nuclear fusion, fusion of nuclei (positively charged) as they as they approach

Coulombicus repulsion increases (FX1/4), to overcome This repution, inhally need to provide enough Coulombian kinetic energy to that they overcome fusion. Thank you. we need to repulsion and undergoes