Atoms Test - 49...

Three photons coming from emission spectra of hydrogen sample are picked up. Their energies are $$12. 1eV, 10.2eV$$ and $$1.9eV$$ . These photons must come from

A sodium atom emits a photon of wavelength $$590\ nm$$ and recoils with velocity $$v$$ equal to 

The ratio of the speed of an electron in the first orbit of hydrogen atom to that in the first orbit of $$He^{+}$$ is

In in nature there may not be an element for which the principal quantum number $$n> 4$$, then the total possible number of elements will be

The electron in a hydrogen atom makes a transition $$n_1\rightarrow n_2$$ whose $$n_1$$ and $$n_2$$ are the principal quantum numbers of the two states. Assume the Bohr model to be valid. The frequency of orbital motion of the electron in the initial state is $${1/27}$$ of that in the final state. The possible value of $$n_1$$ and $$n_2$$ are

In terms of Bohr radius $${a}_{0}$$, the radius of the second Bohr orbit of a hydrogen atom is given by:

An $$\alpha-$$ particle having energy $$10 MeV$$ collides with a nucleus of atomic number $$50$$.Then distance of closet approach will be

The key feature Of Bohr's theory Of spectrum Of hydrogen atom is the quantization Of angular momentum when an electron is revolving around a proton. We will extend this to a general rotational motion to find quantized rotational energy Of a diatomic molecule assuming it to be rigid. The rule to be applied is Bohr's quantization condition.A diatomic molecule has moment Of inertia I. By Bohr's quantization condition its rotational energy in the nth level (n=0 is not allowed) is 

In Bohr's model of hydeogen atom, let PE represent potential energy, and TE the total energy. In going to a higher level:

An electron in hydrogen atom makes a transition $$n_{1}\rightarrow n_{2}$$ where $$n_{1}$$ and $$n_{2}$$ are principal quantum numbers of the two states. Assuming Bohr's model to be valid, the time period of the electron in the initial state is eight times that in the final state. The possible values of $$n_{1}$$ and $$n_{2}$$ are