Explain Bohr- Sommerfeld model of an atom. What is the merit of this model? What are its limitations?

Draw the Bohr- Sommerfeld model for n= 2

Explain the quantum mechanical model of an atom.

In Bohr model of atom :

The first model of an atom was given by

Give a brief account of Thomson model of-atom. What are its limitations ?

The Bohr's model of atoms:

Nuclear model of an atom was put forward by:

Explain Bohr’s model of hydrogen atom and its limitations.

Write the postulates of Bohr's model of hydrogen atom. What are the limitations of Bohr's model of an atom ?