Question

Nobody has seen electrons, protons and neutrons. However, the discovery of Rutherford model, Bohr model and further modification have revolutionized their application in different fields. 

Now, answer the following questions: 

(i) Give one application where electron beam is used. 

(ii) Give one application of proton in medical field. 

(iii) Like electrons, protons in the nuclei also spin. This property of protons has helped to develop machine called nuclear magnetic Resonance (PNMR or simply NMR). What for this machine is used? 

(iv) How has the discovery of neutron been useful as well as harmful to the society? 

Answer 1

(i) Cathode rays (beam of electrons) when focused on a heavy metal like tungsten, molybdenum etc. produce X-rays which find wide applications in medical field. Also, electron microscope which uses a beam of electrons to illuminate a specimen (an extremely small piece) produces a magnified image. 

(ii) Proton therapy is a type of particle therapy which uses a beam of protons to irradiate disease tissue, most often in the treatment of cancer. 

(iii) NMR spectroscopy is used to determine the structure of an organic compound by revealing the hydrogen and carbon skeleton. 

(iv) When a neutron hits uranium, a chain reaction is set up accompanied with evolution of tremendous amount of energy. The energy can be used in the atom bomb for destruction or it can be used in the nuclear reactor to produce electricity.