Question

Describe Bohr’s model of atom.

Answer 1

Hint: To correctly describe Bohr’s model of atom, we should know that Bohr’s model of atom states that electrons in atoms move in circular orbits around a central nucleus.

Step by step answer:
We should know that Bohr model of atom was the further development is the earlier cubic model (1902), the plum-pudding model (1904), the Saturnian model (1904), and the Rutherford model (1911). Now, we should know about the need for the Bohr model of atoms. We should know that early planetary models of the atom suffered from a flaw: in this model electrons spinning in orbit around a nucleus. In terms of electron emission, we can say that a continuous amount of frequencies being emitted and the electron moved closer to the nucleus, it would move faster and would emit a different frequency than those experimentally observed. These planetary models ultimately predicted all atoms to be unstable due to the orbital decay. The Bohr Theory solved this problem and correctly explained the experimentally obtained Rydberg formula for emission lines.
Now, we should know about some properties of electrons under the Bohr Model. We should note that the Bohr Model states that electrons in atoms orbit around the nucleus.
In the second point it states that electrons can only orbit stable orbits without radiating. They orbit at a certain discrete set of distances from the nucleus. These orbits are associated with definite energies and are also called energy shells or energy levels. In these orbits, an electron’s acceleration does not result in radiation and energy loss as required by classical electromagnetic theory.
We should note that electrons can only gain or lose energy by jumping from one allowed orbit to another, absorbing or emitting electromagnetic radiation with a frequency (ν) determined by the energy difference of the levels according to the Planck relation.
So, from the above discussion we know about the Bohr Model of atoms.

Note: Bohr Theory also states that the atom consists of a small positively charged nucleus at its centre. And the whole mass of the atom is concentrated at the nucleus. We should note that the nucleus contains all the protons and neutrons of the atom. Each orbit is associated with a fixed amount of energy. Therefore, these orbits are also known as energy levels or energy shells.