Class 10th Physics Unit 18 Atomic and Nuclear Physics MCQs Short Long Notes

physics 10th notes ch 18

1. In which simplest atom, nucleus has only one proton?


2. Rutherford discovered that the positive charge in an atom was concentrated in a small region called


3. Half-life of plutonium ₉₆PU²³⁶ is


4. The atomic number is represented by


5. The total number of protons in a nucleus or total number of electrons in the orbits is


6. Stable nuclei have atomic number between


7. High energy gamma rays can penetrate at least _________ of air


8. How much energy is released by burning 1 tonne of coal?


9. The Earth and all living things receive radiation from outer space


10. 1eV=


11. Radioactive isotope is used for curing cancerous tumors and cells


12. ________ hydrogen nuclei fuse together to form a helium nucleus


13. The temperature of the centre of Sun is


14. Matter is built from small particles called


15. Which compound readily accumulates in the thyroid gland and can be used for monitoring of thyroid functioning?


16. ___________ are collectively called nucleons.


17. Which radiation does not change its direction?


18. Size of nucleus is


19. Which chemical compounds containing some quantity of radioisotope?


20. How many types of radiation are emitted by radioactive substance?


21. ₂He⁴+₁₃Al²⁷⟶?+₀n¹


22. Which statement is correct about isotopes?


23. Isotopes of an element have the same


24. Nuclear fission was first observed in 1939 by


25. Which particle has shortest penetrating range?


26. Size of electron is


27. The half-life of stable Ar-40 is


28. Hazards of radiation for humans are


29. Atoms of the element which have same number of protons but different number of neutrons are


30. Elements are naturally unstable having atomic number greater than


31. Tritium contains one proton, while protium and deuterium contains


32. When two light nuclei combine to form a heavier nucleus, this process is called


33. Half-life of ₂₇Co⁶⁰ is


34. 1 Bq = ? 


35. Gamma rays are also called


36. Central part of atom is


37. Mass energy equation and theory of relativity was given by


38. Stream of high energy electrons


39. The number of protons and neutrons in a nucleus or atomic mass is represented by


40. Radium⁻²26 has a half-life of


41. The total number of nucleons in a nucleus is


42. Charge on alpha particles is


43. The half –life of C-14 is


44. SI unit for radioactivity is


45. When a tree dies radioactive isotope present in plant starts decaying?


46. Which have the greatest power of ionization as compared to others?


47. Which compound is used for diagnosis of brain tumor?


48. The mass of the proton and neutron is nearly equal to


49. Who accidentally discovered that uranium salt crystals emit an invisible radiation that can darken a photographic plate?


50. Radiation present in atmosphere due to different radioactive substances


51. The number of neutrons in a nucleus is represented by


52. The rate of radioactive decay is proportional to the number of


53. A nucleon is _________ times heavier than electron


54. In each fission reaction energy released


55. Transmutation is


56. During fission of 1kg of Uranium -235 energy released is


57. Size of atom is


58. Nuclear radiation is measured in


59. The phenomenon by which radiations split matter into positive and negative ions is called


Short Questions

A nitrogen nuclide ₇N¹⁴ decays to become an oxygen nuclide by emitting an electron. Show this process with an equation.
Briefly explain how heat is produced in a nuclear reactor?
Compare the mass of different atomic particles with atom
Complete this nuclear reaction: ₉₂U²³⁵ ———> ₅₄X¹⁴⁰ + ? +2 ₀n¹ . Does this reaction involve fission or fusion? Justify your answer .
Define fission fragment.
Define fusion reaction.
Define half-life. With an example.
Define ionization?
Define isotopes with an example
Define natural radioactivity? 
Define nuclear transmutation?
Describe two uses of radioisotopes in medicine, industry or research.
Differentiate between stable and unstable nuclides?
Draw table to show the properties of radiations briefly. 
Explain whether the atomic number can increase during nuclear decay. Support your answer with an example.
How can we make radioactive elements artificially? Describe with a suitable example.
How a helium atom is formed?
How a radioisotope can be used to determine the effectiveness of fertilizer?
How an atom is represented?
How can radioactivity help in the treatment of cancer?
How fusion reaction is the source of energy?
How long will take for complete decay of pure element?
How long would you likely have to wait to watch any sample of radioactive atoms completely decay?
How many types of radiations are emitted by radioactive substance? Name them
How much of a 1 g sample of pure radioactive substance would be left undecayed after four half- lives?
Is it possible for an element to have different types of atoms? Explain.
Nuclear fusion reaction is more reliable and sustainable source of energy than nuclear fission chain reaction. Justify this statement with plausible arguments.
Tritium is radioactive isotope of hydrogen. It decays by emitting an electron. What is the daughter nucleus?
What is difference between atomic number and atomic mass number? Give a symbolical representation of a nuclide.
What is the difference between natural and artificial radioactivity?
What is meant by background radiations? Enlist some sources of background radiations.
What nuclear reaction would release more energy, the fission reaction or the fusion reaction? Explain.
What a secondary radiations? 
What are cosmic radiation? 
What are nucleons?
What are radioisotopes?
What are stable nuclides?
What are the three basic radioactive decay processes and how do they differ from each other?
What are unstable nuclides?
What do know about discovery of an atom?
What do you know about atom?
What do you know about fission chain reaction?
What do you know about the placement of atomic particles in an atom?
What do you mean by the term radioactivity? Why some elements are radioactive but some are not?
What do you understand by half-life of a radioactive element?
What information about the structure of the nitrogen atom can be obtained from its nuclide ₇N¹⁴? In what way atom in ₇N¹⁴ is different from the atom in ₇N¹⁶?
What is a radioactive tracer?
What is atomic mass number?
What is atomic number?
What is by nuclear fission?
What is meant by penetrating ability?
What is neutron number?
What is the commonly used unit of radioactivity?
What is the contribution of Marie Curie and Pierre? 
What is the safe limit of radiations per year?
What is the safe limit of X-rays for a patient? 
What is the unit of nuclear radiation?
Which has more penetrating power, an alpha particle or a gamma ray photon?
Which type of natural radioactivity leaves the number of protons and the number of neutrons in the nucleus unchanged?
Why positively charged proton in nucleus doesn’t fly a part in response of huge electrical force of repulsion between them?
Why the beam of radiation only directed to cancerous cells?
Why the mass of final nucleus is always less than the masses of original nuclei?
Write a note on nature of radiations
Write any two properties of alpha particles.
Write any two properties of beta particles.
Write any two properties of gamma rays.
Write the alpha decay process for . Identify the parent and daughter nuclei in ₉₁Pa²³⁴ this decay.
Write the ranges of radiations in air. 
Write uses of radioisotopes.
Write uses of tracers.

Long Questions

A sample of certain radioactive element has a half-life of 1500 years. If it has an activity of 32000 counts per hour at the present time, then plot a graph of the activity of this sample over the period in which it will reduce to 1/16 of its present value.
Ashes from a campfire deep in a cave show carbon-14 activity of only one-eighth the activity of fresh wood. How long ago was that campfire made?
Carbon-14 has a half-life of 5730 years. How long will it take for the quantity of carbon-14 in a sample to drop to one-eighth of the initial quantity?
Cobalt-60 is a radioactive element with half-life of 5.25 years. What fraction of the original sample will be left after 26 years?
Describe the nature and properties of radioactive radiations?
Differentiate between atomic number and atomic mass with examples.
Half-life of a radioactive element was found to be 4000 years. The count rates per minute for 8 successive hours were found to be 270, 280, 300, 310, 285, 290, 305, 312. What does the variation in count rates show? Plot a graph between the count rates and time in hours. Why the graph is a straight line rather than an exponential?
Is radioactivity a spontaneous process? Elaborate your answer with a simple experiment.
Technetium-99 m is a radioactive element and is used to diagnose brain, thyroid, liver and kidney diseases. This element has half-life of 6 hours. If there is 200 mg of this technetium present, how much will be left in 36 hours.
The half-life of ₇N¹⁴ is 7.3 s. A sample of this nuclide of nitrogen is observed for 29.2 s. Calculate the fraction of the original radioactive isotope remaining after this time.
What are background radiations?
What are common radiation hazards? Briefly describe the precautions that are taken against them?
What are radioisotopes? Write the uses of radioisotopes.
What are the three basic radioactive decay processes and how do they differ from each other?
What do you mean by half life of a radioactive element?
What do you mean by natural radioactivity?
What is nuclear fusion?
Write in detail about fission reaction.

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