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प्रश्न
What is meant by radioactivity?
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उत्तर
Elements with a high atomic number such as uranium, thorium, radium have a property of spontaneously emitting invisible, highly penetrating and high energy radiation. This property is called radioactivity. The nucleus of radioactive elements is unstable.
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संबंधित प्रश्न
When does the nucleus of an atom tend to become radioactive?
Answer the following questions based on a hot cathode ray tube.
What will happen to the beam when it passes through the electric field?
What are free electrons?
How can they be made to leave the metal surface? (State any two ways)
State the energy conversion taking place in a cathode ray tube
Name a gas caused by the Greenhouse effect
What is thermionic emission?
What do you mean by Atomic number
State two similarities and two dissimilarities between the γ-rays and X-rays.
In following fig. shows a mixed source S of alpha and beta particles in a thick lead container. The particles pass through a magnetic field in a direction perpendicular to the plane of paper (inwards as shown by x). State and show in the diagram how the particles get affected.
Explain the use of radioactive in the field of medicine, agriculture and industry.
What are the uses of radioactive isotopes in following?
(a) Medical field,
(b) Agriculture,
(c) Industries?
A nucleus is \[\ce{^24_11 Na}\] β-radioactive.
Write the equation represent β-decay.
Define bound electrons.
State two characteristics of the substance used as thermionic emitter.
State any two uses of cathode rays.
In a cathode ray tube state the purpose of the fluorescent screen.
What is meant by Radioactivity?
An electrons emitter must have how much work function and melting point.
Two radioactive nuclei are represented by xAp and yAq and when p and q are mass numbers and x, y are the atomic number. How can the products be represented, i .e., what are the new values of p, q. x and y after the emission of an α-particle and a β-particle from A and B respectively.
Which part of the atom undergoes a change in the process of radioactive decay?
Which of the following statements is/are correct?
- α particles are photons
- Penetrating power of γ radiation is very low
- Ionization power is maximum for α rays
- Penetrating power of γ radiation is very high
Heavy radioactive elements eventually turn into ______.
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be ______.
A deuteron strikes 8O16 nucleus with subsequent emission of an alpha particle. Identify the nucleus so produced:
When an α-particle of mass m moving with velocity ν bombards on a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on m as:
