Limitations of bohr's atomic model class 12

State the three postulates of Bohr's theory of hydrogen atom

 The absence of some facts in Rutherford's atomic model was guessed by Niels Bohr and taking the help of Planck's quantum theory, Bohr prepared a model of his own. This model was introduced by Niels Bohr in 1913.

It is also called the Rutherford–Bohr model because it was made by improving and updating some conditions in Rutherford's atomic model.

According to Bohr, the electron revolves around the nucleus in the orbits of fixed energy.

(1). If the electron is revolving in the orbits near the nucleus, then its energy will be low and if the electron is revolving in the orbits away from the nucleus then its energy value will be high.

(2). The electron does not emit any energy in its fixed orbits while revolving around the nucleus, but its energy changes as it moves from one orbit to another.

 (3). An electron emits energy while moving from higher orbits to lower orbits and acquires the required energy while moving from lower orbits to higher orbits.

(4). The angular momentum of an electron in an atom can have certain definite or discrete values and not any value of its own. This is given as :

mvr = nh/2π

Here n = 1, 2, 3, .......  is an integer. 

n is called the principal quantum number of the orbit.

(5). The force required to rotate the electron in its fixed orbits is obtained by the centripetal force.

(6). When an electron gets external energy, it goes to higher orbits, i.e.it goes into an excited state. In an excited state i.e. in higher orbits the electron can stay for only 10-8 seconds and again returns to lower orbits and while returning emits magnetic radiation (energy).

Limitations of Bohr's atomic model class 12

(1). The Zeeman effect cannot be explained based on this Bohr model.

(2). The intensity of the spectral lines cannot be explained.

(3). This model is true only for single-electron atoms such as H, He+, Na+1, Li2+, etc.

(4). In some atoms like Na etc., two spectrum lines are visible, it cannot be explained by this atomic model.

(5). Bohr considered the nucleus of an atom to be stationary but the nucleus keeps rotating about its axis.

Conclusion:

Limitations of Bohr's atomic model class 12 is an important topic. That is why I tried my best to complete it efficiently.

Thank you ❤️