Home
Class 9
CHEMISTRY
(a) state the postulates stated by neils...

(a) state the postulates stated by neils bohr in order to overcome the objection as raised against Ruthford's model of atom.
(b) summarise the rules for the distrubution of elctrons in the first eighteen elements

Text Solution

Verified by Experts

(a) For answer consult section 4.5
(b) For answer consult section 4.9
Promotional Banner

Topper's Solved these Questions

  • STRUCTURE OF ATOM

    DINESH PUBLICATION|Exercise Higher order thinking skilll based questions|5 Videos

  • STRUCTURE OF ATOM

    DINESH PUBLICATION|Exercise Multiple choice question|26 Videos

  • STRUCTURE OF ATOM

    DINESH PUBLICATION|Exercise Short Answer Question|45 Videos

  • MATTER IN OUR SURROUNDINGS

    DINESH PUBLICATION|Exercise (LAQs) Long Answer Questions|5 Videos

Similar Questions

Explore conceptually related problems

(a) Describe the Rutherford's model of an atom. State one drawback of Rutherford's model of the atom (b) The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it ? What is the atomic number of the element ?

Neils Bohr has a major contribution towords the structure of atom. He has given Bohr's Bury rules for the distribution of electrons in the various shells in an atom. Apart from that, he has also introduced the concept of ground state and excited states for an electron. But Bohr theory does suffer from certain defects. The present picture of the atom is mainly due to the researches carried by Heisenberg. (i) State the Heisenberg's uncertainty principle. (ii) Give its mathemetical form. (iii) Why does the principle have no utility in daily life ?

State Bohr second postulate for atomic model. Express it in its mathematical form.

The electric current I created by the electron in the ground state of H atom bohr model in terms of bohr radius (a_0) and velocity of electron in first orbit v_0 is

(a) (i) Find the wavelength of the radiation required to excite thye elctron in Li(++) from the first to the third Bohr orbit. (ii) How many spectal lines are observed in the emission spectrum of the above excited system ? (b) The energy needed to detach the electron of a hydrogen-like ion in ground state in 4 rydberg. (i) What is the wavelength of the radiation emitted when the electron jumps from the first excited state ot the ground state ? (ii) What is the radius of first orbit ? (c ) A hydrogen sample is prepared in a particular excited state A. Photons of energy 2.55 eV get absorbed into the sample to take some electrons to a further excited state B. Find the quantum number of the A and B. (d) A hydrogen atom in a state having a binding energy of 0.85 eV makes transition to a state with excitation energy 10.2 eV. (i) Identify the quantum number n of the upper and the lower energy states. Find lambda .

Three elements 'X', 'Y' and 'Z' have atomic numbers 7, 8 and 9 respectively. (a) State their positions (Group number and period number both) in the Modern Periodic Table. (b) Arrange these elements in the decreasing order of their atomic radii. (c) Write the formula of the compound formed when 'X' combines with 'Z'.

DINESH PUBLICATION-STRUCTURE OF ATOM -Long Answer Question
  1. (a) Give the schematic atomic structures of chlorine atom and chloride...

    Text Solution

    |

  2. Answer the following in one line or two: (a) what is the maximum nu...

    Text Solution

    |

  3. Which observations in scatteing experiment led Rutherford to make the ...

    Text Solution

    |

  4. With the help of suitable acitivies shows that (i) cathode rays trav...

    Text Solution

    |

  5. The average atomic mass of a sample of an element X is 16.2 mu. What i...

    Text Solution

    |

  6. Give reasons for the following: (a) Isotopes of an element are chemi...

    Text Solution

    |

  7. The following data repersents the distribution of electons protons and...

    Text Solution

    |

  8. An atom of an elements has two electrons in outermost M shell state it...

    Text Solution

    |

  9. (a) why are the chemical properties of the isotopes same? (b) Draw b...

    Text Solution

    |

  10. (a) In the gold foil experiment , what observations led Rutherford t...

    Text Solution

    |

  11. (a) state the postulates stated by neils bohr in order to overcome the...

    Text Solution

    |

  12. Define isotopes why do isotopes have same atomic number but differente...

    Text Solution

    |

  13. Why do helium, neon and argon have a zero valency?

    Text Solution

    |

  14. The ratio of the radii of hydrogen atom and its nucleus is ~ 10^(5). ...

    Text Solution

    |

  15. Enlist the conclusions drawn by Rutherford from his alpha-ray scatteri...

    Text Solution

    |

  16. In what way is the Rutherford's atomic model different from that of Th...

    Text Solution

    |

  17. What were the drawbacks of Rutherford's model of an atom?

    Text Solution

    |

  18. What are the postulates of Bohr's model of an atom?

    Text Solution

    |

  19. Show diagramatically the electron distributions in a sodium atom and a...

    Text Solution

    |

  20. In the gold foil experiment of Geiger and Marsden, that paved the way ...

    Text Solution

    |