Limitations of Bohr's Model

Q. Which of the following statements are incorrect regarding the Bohr's Atomic Model ?

1. Bohr's model was a huge success as it could successfully explain the Hydrogen line spectra
2. Bohr's model ended up being unsuccessful due to its limitation for single electron systems
3. Bohr's Quantization rule was never validated by any theoretical evidence
4. Bohr's model was limited to absorption only from ground state of an atom

Q. Which of the following questions, the Bohr's atomic model was not able to provide an answer for:

1. Why electrons have a license to "not" follow Maxwell's law of radiation in certain orbits?
2. Why the transitions between certain orbits are more favorable?
3. Why does the electron revolve around the nucleus and can't remain stationary?
4. Why is it necessary for the electrons to emit a photon while transitioning from higher to lower orbits?

Q. In Moseyls law $\sqrt{v}=a(z-b)$, the value of the screening constant for $K-$series and $L-$series of $X-$series rays are respectively :

1. $1,4$
2. $4,6$
3. $2,4$
4. $1,6.4$

Q. What are the limitations of Bohr's theory of a hydrogen atom?

Q. The value of Bohr Magneton is given by :

1. $eh/4\pi mc$
2. $e^{2}h/2\pi mc$
3. $e/4\pi m$
4. $eh/4\pi m$

Q. Imagine removing one electron from ${}_{2}H{e}^4$ and ${}_{2}H{e}^3$. Their energy levels, as worked out on the basis of Bohr model will be very close. Explain why.

Q. The simple Bohr model is not applicable to $H{e}^4$ atom because

1. $H{e}^4$ is an inert gas.
2. $H{e}^4$ has one more electron.
3. $H{e}^4$ has neutrons in the nucleus.
4. Electrons are not subject to central forces.

Q. In a hypothetical system a particle of mass m and charge -3q is moving around a very heavy particle having charge q. Assuming Bohr's model to be time to this system, the orbital velocity of mass m when it is nearest to heavy particle is

1. $\frac{3q^2}{2{ϵ}_{0}h}$
2. $\frac{3q^2}{4{ϵ}_{0}h}$
3. $\frac{3q}{2{ϵ}_{0}h}$
4. $\frac{3q}{4{ϵ}_{0}h}$

Q. For the ground state, the electron in the H - atom has an angular momentum = h, according to the simple Bohr model. Angular momentum is a vector and hence there will be infinitely many orbit with the vector pointing in all possible directions. In actually, this is not true,

1. because Bohr's model gives incorrect values of angular momentum.
2. because only one of these would have a minimum energy.
3. angular momentum must be in the direction of spin of electron
4. because electrons go around only in horizontal orbits.

Q. The simple Bohr model cannot be directly applied to calculate the energy levels of an atom with many electrons. This is because

1. of the electrons colliding with eachother
2. of screening effects
3. the force between the nucleus and an electron will no longer be given by Coulomb's law.
4. of the electrons, not being subject to a central force.