```Derivation of Angular Momentum from de Broglie Equation:
According to Bohr’s model, the electron revolves around the nucleus in circular orbits. According to de Broglie concept, the electron is not only a particle but has a wave character also.

If the wave is completely in phase, the circumference of the orbit must be equal to an integral multiple of wave length (λ)
Therefore 2πr = nλ
where ‘n’ is an integer and ‘r’ is the radius of the orbit
But λ = h/mv
∴ 2πr = nh /mv   or mvr = n h/2π

which is Bohr’s postulate of angular momentum, where ‘n’ is the principal quantum number.
“Thus, the number of waves an electron makes in a particular Bohr orbit in one complete revolution is equal to the principal quantum number of the orbit”.
Alternatively:

Number of waves ‘n’    = 2πr / λ  = 2πr / h/mv  = 2πmvr / h
Where v and r are the velocity of electron and radius of that particular Bohr orbit in which number of waves are to be calculated, respectively.

The electron is revolving around the nucleus in a circular orbit. How many revolutions it can make in one second?
Let the velocity of electron be v m/sec. The distance it has to travel for one revolution 2πr, (i.e., the circumference of the circle).
Thus, the number of revolutions per second is = v / 2πr
Common unit of energy is electron volt which is amount of energy given when an electron is accelerated by a potential of exactly 1 volt. This energy equals the product of voltage and charge. Since in SI units coulombs x volts = joules, 1 eV numerically equals the electronic charge except that joule replaces coulombs.```
Related Resources
Problems with Solutions

Problems with Solutions True and False Problem:...

Calculation of velocity of Electron

Calculation of Velocity: We know that mvr =...

Quantum Numbers

QUANTUM NUMBERS An atom contains large number of...

Atomic Models

Atomic Models We know the fundamental particles of...

Quantum Mechanical Model of Atom

Quantum Mechanical Model of Atom...

Discovery of Electron Proton and Neutron

Discovery of Electron, Proton & Neutron Lets...

Fundamental Particles

Relation-Kinetic Energy and Wavelength

Relation between Kinetic Energy and Wavelength:...

Atomic Spectrum

ATOMIC SPECTRUM If the atom gains energy the...

Discovery of Proton

DISCOVERY OF PROTON: POSITIVE RAYS OR CANAL RAYS...

Atomic Structure Terms

ATOMIC TERM Nuclide: Various species of atoms in...

Hunds rule of Maximum Multiplicity

Hund’s Rule of Maximum Multiplicity: This...

Solved Questions of Atomic Structure Part I

Solved Questions of Atomic Structure Part I...

Radius and Energy Levels of Hydrogen Atom

Radius and Energy Levels of Hydrogen Atom:...

Dual Nature of matter and Photoelectric Effect

Dual Nature of Matter and Photoelectric Effcet...

Characteristics of Wave

Characteristics of Wave SOME IMPORTANT...

A-Scattering Experiment

A-Scattering Experiment Conclusions of...

Heisenbergs Uncertainty Principle

HEISENBERG’S UNCERTAINTY PRINCIPLE All...

Bohrs Atomic Model

BOHR’S ATOMIC MODEL Bohr developed a model...

Calculation of Energy of Electron

Calculation of Energy of an Electron: The total...

Hydrogen Atom

HYDROGEN ATOM If an electric discharge is passed...

Objective Questions of Atomic Structure

Objective Questions of Atomic Structure Problem:...

Plancks Quantum Theory

PLANCK’S QUANTUM THEORY When a black body is...

Electronic Configuration

Electronic Configuration Rules for filling of...

Discovery of Neutron

DISCOVERY OF NEUTRON After the discovery of...

Shapes and Size of Orbitals

Pauli’s Exclusion Principle: According to...

Limitations of Bohrs Theory

Merits of Bohr’s Theory: * The experimental...

Photoelectric Effect

PHOTOELECTRIC EFFECT Sir J.J. Thomson, observed...