Class 10 Physics Chapter 9 Notes

Complete Notes on Chapter No.18:  class 10 physics chapter 9 notes written by Mr. Tayyab Shahzad. These computerized notes are very helpful in the preparation of class 10 physics chapter 9 notes for students of the Physics and these are according to the paper patterns of all Punjab boards.

• Important physics chapter 9 class 10 notes for all students of Punjab  Textbook Board.
• Topics which are discussed in the notes are given below:
• Atomic and Nuclear Physics Exercise Multiple Choice Questions ( MCQs ) with Correct Answers.
• Atomic and Nuclear Physics Exercise Short Questions with Answers.
• Important 10th class physics chapter 18 mcqs for all students of Punjab  Textbook Board.
• What is difference between Atomic Number and Atomic Mass number?
• What do you mean by the term radioactivity?
• How can we make radioactive elements artificially?
• Explain whether the atomic number can increase during nuclear decay?
• Important class 10 physics chapter 9 notes pdf for all students of Punjab  Textbook Board.
• What do you understand by half-life of a radioactive element?
• Is radioactivity a spontaneous process?
• What is meant by Background radiations?
• Describe two uses of radioisotopes in medicine, Industry or research? 
• Important 10th class physics chapter 9 notes for all students of Punjab  Textbook Board.
• What are two common radiation hazards? Briefly describe the precautions that are taken against them.
• What is meant by cosmic radiations.
• Nuclear fusion reaction is more reliable and sustainable source of energy than nuclear fission chain reaction?
• Define Isotopes.
• Define nuclear transmutation.
• Important 10th physics notes for class 10 chapter 9 for all students of Punjab  Textbook Board.
• Define nuclear fusion. Write its equation.
• Define Carbon dating.
• Define Penetrating Power.
• What is meant by tracer?
• Write two properties of 𝑎-Particle.
• Important class 10th chapter 9 physics notes for all students of Punjab  Textbook Board.
• Define radioactive isotopes.
• Difference between stable and unstable nuclei?
• Write half-life of Hydrogen, Lead, Uranium, and Carbon.
• Define atom and write its basic particles.
• Define Electron Volt.
• Important physics class 10th chapter 9 notes for all students of Punjab  Textbook Board.
• Penetrating Ability: The strength of radiations to penetrate a certain material is called penetrating power. The alpha particle has the shortest range because of its strong interacting or ionizing power. The gamma rays can penetrate a considerable thickness of concrete. It is due to their large speed and neutral nature. The beta radiation strongly interacts with matter due to its charge and has a short range as compared to gamma radiations. The relative penetrating abilities of three kinds of radiations.
• Alpha particle has a range of only a few centimetres in air. Beta particles have range of several metres in air. 
• Important physics notes for class 10 chapter 9 numericals for all students of Punjab  Textbook Board.
• HALF-LIFE AND ITS MEASUREMENT: Process of radioactivity is random and the rate of radioactive decay is proportional to the number of unstable nuclei present. In the process, a constant fraction of large number of unstable radioactive nuclei decays in a certain time. So the life time of the unstable nuclei is unlimited and is difficult to measure. We can get the idea about decay rate by the term half-life.
• Important 10th class physics chapter 18 notes for all students of Punjab  Textbook Board.
• "The time during which half of the unstable radioactive nuclei disintegrate is called the half-life of the sample of radioactive element".
• Every radioactive element has its own characteristic hal-flife. For example, radium-226 has a half-life of 1620 years, which means that half of a radium-226 sample will be converted to other elements by the end of 1620 years. In the next 1620 years, half of the remaining radium will decay, leaving only one-fourth the original amount of radium, and so on.
• Important 10th class physics chapter 18 test for all students of Punjab  Textbook Board.
• If the half-life of the radioactive element is T 1/2, then at the end of this time the number of atoms in the sample will become half i.e.,
• Example: The activity of a sample of a radioactive bismuth decreases to one-eight of its original activity in 15 days. Calculate the half-life of the sample.
• Important 10th class physics chapter 18 short questions for all students of Punjab  Textbook Board.
• Example: A radioactive element has a half-life of 40 minutes. The initial count rate was 1000 per minute. How long will it take for the count rate to drop to (a) 250 per minutes (b) 125 per minutes (c) Plot a graph of the radioactive decay of the element.
• Important class 10th physics chapter 18 important questions for all students of Punjab  Textbook Board.