Historical development of atomic models, Physics

Assignment Help:
Historical development of atomic models
  • In olden days there was an idea that all matter is made of tiny indivisible particles.
  • When Thomson discovered electron, this idea became value less.
  • In 1898 Thomson proposed his model of atom 
  • According to this model positive charge is distributed uniformly over the entire body of the atom while the electrons are embedded in it.
  • However this model failed as it could not explain the observed spectral lines emitted by an atom.
  • Later in 1903 Lenard proposed his atomic model.
  • According to him a lot of empty space exists in an atom. He could not explain the stability and mass of an atom.
  • In 1911 Rutherford proposed his model of atom. According to him positively charged mass is situated at the centre and electrons are revolving around it.
  • This model failed to explain the stability of an atom.
  • In 1912, in order to account for the stability of atom, Neils Bohr, proposed a different model.
  • According to this model

i ) Electrons in an atom revolve around the nucleus in circular orbits just as the planets revolve round the sun.
ii) The electrons revolve only in certain permitted orbits called ‘stationary orbits' and do not radiate energy while in such orbits.
iii) Whenever an electron jumps from one stationary orbit to another, absorption or emission of energy takes place. This theory could explain the spectral lines emitted by different elements.


Related Discussions:- Historical development of atomic models

What do you understand by end correction, What do you understand by "End co...

What do you understand by "End correction" in resonating air column? What occures to the frequency of a tuning fork a) When it is loaded with a little wax and b) When it is file

Explain archimedes'' principle, It explains that when an object is immersed...

It explains that when an object is immersed partly or completely in a liquid, it loses in weight similar to the weight of the liquid displaced by it. Let w1 be weight of an obje

Determine number of neutrons in nucleus of the atom, An atom has 26 electro...

An atom has 26 electrons and its atomic weight is 56. The number of neutrons in the nucleus of the atom will be : (1) 26      (2) 30        (3) 36                     (

Determine the Effect of air resistance, An object in free fall has an accel...

An object in free fall has an acceleration of 9.80 m/s 2 assuming that there is no air resistance. What is the speed of an object dropped from the top of a tall cliff 3.50 s a

Electrons, after formation of bond where does electron rotate

after formation of bond where does electron rotate

Infrared radiations and ultra violet radiations, Infrared radiations and Ul...

Infrared radiations and Ultra Violet radiations: What are infrared radiations and Ultra Violet radiations? Ans: Infrared: Wavelengths larger than visible light 2. Wav

Describe newton''s first law, Each object continues to be in its state of u...

Each object continues to be in its state of uniform motion or of rest in a straight line unless completed by some external force to perform otherwise. Newton's first law is real

Define yttrium aluminium garnet doped with neodymium laser, Define the Yttr...

Define the Yttrium Aluminium Garnet doped with Neodymium laser in short. Nd:YAG laser: a. Nd:YAG, this term stands for Yttrium Aluminium Garnet doped along with Neodymium

Boolean algebra, (1) In Boolean algebra only two types of state variables (...

(1) In Boolean algebra only two types of state variables (0 and 1) are permitted. (2) The variables (A, B, C ....) of Boolean algebra are subjected to three operations.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd