Bohr Model of The Atom Modern Atomic Theory


 
 
Concept Explanation
 

Bohr Model of The Atom Modern Atomic Theory

Bohr’s Model of an Atom: To overcome the objections raised against Rutherford’s model of the atom, Neil Bohr put forward the following postulates about the model of an atom:

  • Atom consists of positively charged nucleus around which electrons revolve in discrete orbits, i.e. electrons revolve in certain permissible orbits and not just in any orbit.
  • Each of these orbits are associated with certain value of energy. Hence, these orbits are called energy shells or energy levels. As the energy of an orbit is fixed (stationary), orbit is also called stationary state.
  • Starting from nucleus, energy levels (orbits) are represented by numbers (1, 2, 3, 4 etc.) or by alphabets (K, L, M, N etc.).
  • Energy of an electron remains same as long as it remains in discrete orbit and it does not radiate energy while revolving.
  • When an electron jumps from a lower energy to a higher one, some energy is absorbed while some energy is emitted when the electron jumps from a higher energy level to a lower one.
  • Normally, the electrons present in first energy level (E1) have lowest energy. Energies increases on going towards outer energy levels.
  • Evidences in Support of Divisibility of Atom: Following observations show that atom is made up of different particles like electrons, protons and neutrons, i.e. atom is divisible:(i)    Formation of ionic compounds is possible due to the formation of ions which involves the transfer of electrons.(ii)    Presence of isotopes for the same element is possible due to the difference in the number neutrons.

    Sample Questions
    (More Questions for each concept available in Login)
    Question : 1

    Which of the following  statement / statements are correct :

    (a) The electrons present in first energy level (E1) have lowest energy

    (b) Atom consists of negatively charged nucleus.

    (c) Starting from nucleus, energy levels (orbits) are represented by numbers.

    (d) Starting from nucleus, energy levels (orbits) are represented by symbols.

    Right Option : C
    View Explanation
    Explanation
    Question : 2

    The Statement that does not belong to Bohr's model of atom, is:

    Right Option : D
    View Explanation
    Explanation
    Question : 3

    Which of the following statement / statements are correct :

    (a) Energy of an electron remains same as long as it remains in discrete orbit and it does not radiate energy while revolving.

    (b) Starting from nucleus, energy levels (orbits) are represented by numbers (1, 2, 3, 4 etc.) or by alphabets (K, L, M, N etc.).

    Right Option : C
    View Explanation
    Explanation
     
     
     


    Students / Parents Reviews [10]