Postulates of Bohr’s Atomic Model
The major postulates of Bohr’s Atomic Model are,
- In an atom, electrons revolve around the nucleus in some fixed circular orbits called shells.
- These shells are also called Stationary Orbits.
- Electrons while revolving in these orbits do not lose any energy. Also, each cell has a fixed energy associated with it.
- In these fixed orbits the angular momentum of the electron is an integral multiple of “h/2π”, where “h” is Planck’s constant.
Therefore the angular momentum “L” of the revolving electron is,
L = nh/2π
where,
n is integer 1,2,3….. known as a principal quantum number
h is Plank’s constant
- The energy of an electron revolving in a stationary orbit remains constant. Energy is emitted from an atom only when an electron jumps from the orbit of higher energy to the orbit having low energy.
- When an electron jumps from one energy level to another energy level it radiates energy. For example, if an electron jumps from orbit with energy Ei to orbit with energy Ef it releases a photon of energy hv which is calculated as,
hv = Ei – Ef
Bohr’s Model of an Atom
Bohr’s Model is an atomic model proposed by Danish Physicist Niels Bohr in 1913. According to this model, in an atom, the electrons revolve around the nucleus in definite energy levels called orbits/shells. This model provides a basic understanding of the concept of the atom and its constituents.
Let’s learn more about Bhor’s Atomic Model, its limitations, and others in detail in this article.