Bohr Model

Why was a change in the Bohr Model of atom required? Due to which important development concept of movement of an electron in an orbit was replaced by the concept of probability of finding electron in an orbital?what is the name given to the changed model fo atom?

In the Bohr model of the hydrogen atom, what is the de-Broglie wavelength for the electron when it is in (a) the n=1 level? (b) Then n=4 level? In each case, compare the de-Broglie wavelength to the circumference 2pir_n of the orbit.

According to Bohr's Model of hydrogen atom

Bohr's model of atom is not in agrement with

Bohr's model can explain

In Bohr's model of hydrogen atom ,

Bohr's model can explain

Which of the following are the limitation of Bohr's model ?

Bohr's model is applicable to which ion?