Question

Bohr model can explain:
A. The spectrum of hydrogen atom only
B. Spectrum of an atom or ion containing two electron
C. The spectrum of hydrogen molecules
D. Solar spectrum

Answer 1

Hint: We need to study Bohr’s model thoroughly to understand what it does. The Bohr model is also known as Bohr’s atomic model. Rutherford’s model explained the motion of electrons around the nucleus in circular orbits but could not explain the radiation emitted by these electrons. A Danish physicist Niels Bohr modify Rutherford’s model which gave the remedy to this limitation.

Complete step by step answer:
We need to know that the Niels Bohr proposed a new model of an atom that said that electrons around a nucleus do not emit energy as they move in their orbits around the nucleus but exist in a constant energy state known as a stationary state which is at a fixed distance from the nucleus.
He used the hydrogen atom to explain this theory. He worked on the emission spectra of hydrogen and explained that electrons can jump from a lower to a higher orbit by the addition of energy but when this energy is removed, the electrons move back to their original ground state which emits energy called a photon or a quantum of light.
We must remember that this theory of his is known as the planetary model where electrons move in fixed paths around the nucleus called orbits whose energy is fixed. This planetary model explains the emissions of a hydrogen atom but could not explain the emission spectra of other atoms.

So, the correct answer is Option A.

Note: It must be noted that Bohr used the Planck’s constant to obtain the formula for the energy levels of the hydrogen atom. The orbits are labeled by a quantum number “n” (n=1 if the electron is in the ground state). To summarize the Bohr’s model, electrons emit energy in the form of light when they travel to a lower energy level which gives the spectrum of hydrogen. It is limited to one electron system only.