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प्रश्न
Describe Bohr’s model of the atom.
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उत्तर
A Danish physicist, Neils Bohr, offered the following postulates for modifying the Rutherford model.
- Atoms have a core nucleus surrounded by electrons.
- An atom comprises a small, positively charged nucleus at the centre, around which electrons travel in circular paths known as orbits or shells.
- Each orbit has a defined amount of energy; hence, they are known as energy levels or energy shells.
- The energy shells' order will be
K < L < M < N < O < .........
or, 1 < 2 < 3 < 4 < 5 < ......... - An electron does not lose or gain energy while remaining in a specific orbit.
- When an electron moves in an orbit, it absorbs and emits no energy. However, energy is absorbed when it moves from a lower to a higher orbit, and energy is emitted when it moves from a higher to a lower orbit.
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संबंधित प्रश्न
Name the scientists who described the arrangement of electrons in an atom.
In the figure given alongside
(a) Name the shells denoted by A,B, and C. Which shell has least energy
(b) Name X and state the charge on it
(c) The above sketch is of …………. Model of an atom
Give the postulates of Bohr's atomic model
State in brief the drawbacks of Rutherford's atomic model correlating them with the postulates of Bohr’s atomic model.
State true or false. If false, correct the statement.
Smaller the size of the orbit, lower is the energy of the orbit.
An atom with 3 protons and 4 neutrons will have a valency of
The atomic model based on quantum theory was first proposed by ______.
The scientist who proposed the atomic model based on the quantisation of energy for the first time is ______.
Given below are two statements:
Statement I: Atoms are electrically neutral as they contain equal number of positive and negative charges.
Statement II: Atoms of each element are stable and emit their characteristic spectrum.
In the light of the above statements, choose the most appropriate answer from the options given below:
A particle of mass ‘m’ and charge ‘−2q’ is moving around a very heavy particle having charge ‘q’. If Bohr’s model is to be used then the orbital velocity of mass ‘m’ when it is nearest to the heavy particle is (in magnitude) (ε0 = permittivity of free space, h = Planck’s constant) ______.
