Question

Bohr’s atomic model can explain the spectrum of:
A.Hydrogen atoms only
B.Atoms or ions which are unielectron
C.Atoms or ions which have only two electrons
D.Hydrogen molecule

Answer 1

Hint:Bohr’s model of the atom is a modification of Rutherford’s model of an atom where he explained that the nucleus is surrounded with negatively charged electrons. In this model, Bohr explained that the electrons move in a fixed orbit and each orbit has a fixed energy level.

Complete step-by-step answer:In Bohr’s model, he basically explained about the electrons and their energy levels. The electron that is located away from the nucleus carries more energy. The electrons that are located close to the nucleus carry less energy.
Now let us discussed about the postulates given by Bohr in Bohr’s atomic model-
In an atom, the negatively charged particles that are electrons revolve around the positively charged particle that is the nucleus in a circular path known as orbits. Each orbit contains fixed energy.
The energy of the electron does not depend upon the time. The electron moves from lower energy state to higher energy state when a required amount of energy is absorbed or emitted by the electron.
The frequency of energy emitted or absorbed during the transition between the two different energy states-
$$\upsilon ={\displaystyle \frac{\mathrm{\Delta }E}{h}}$$
Where, $\upsilon$ is the frequency
$\mathrm{\Delta }E$ is the change in the energy of the quantum of electromagnetic radiation
$h$ is the Planck’s constant
Bohr’s theory is only applicable to unielectron that means atoms having only one electron in their shell. For example- hydrogen atoms that have only one electron in their shell.

Therefore, the correct option is B.

Note:In this question, we have concluded that the bohr’s theory is applicable to only hydrogen like ions that are mono electrons. For example $H{e}^{+},L{i}^{2+}$ . It does not explain about the spectra of ions having two or more than two electrons. It violates the Heisenberg uncertainty principle.