The ratio of the speed of the electron in the first Bohr orbit of hydrogen and the speed of light is equal to (where $e,h$ and $c$ have their usual meanings)

The radius of the Bohr orbit in the ground state of hydrogen atom is $0.5\,\,{A^0}$. The radius of the orbit of the electron in the third excited state of $H{e^ + }$ will be

In a hydrogen atom, the kinetic energy of the electron in a particular Bohr orbit is $2.18 imes 10^{-18}$ J. What is the total energy of the electron in this orbit?

If the kinetic energy of an electron in a particular Bohr orbit is K, what is the potential energy in terms of K?

In a hydrogen atom, an electron transitions from the 3rd orbit to the 2nd orbit, emitting a photon of wavelength $\lambda$. If the electron transitions from the 4th orbit to the 2nd orbit, what will be the wavelength of the emitted photon?

In a beryllium atom, if ${a_0}$ be the radius of the first orbit, then the radius of the second orbit will be will be in general

In the Bohr’s hydrogen atom model, the radius of the stationary orbit is directly proportional to ($n =$ principle quantum number)

Consider an electron in the ${n^{{\rm{th}}}}$ orbit of a hydrogen atom in the Bohr model. The circumference of the orbit can be expressed in terms of the de Broglie wavelength $\lambda$ of that electron as

If the total energy of an electron in an atom is $-2.18 eV$, what is the magnitude of its potential energy?

Whenever a hydrogen atom emits a photon in the Balmer series

The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561\,\mathop {\rm{A}}\limits^ \circ  . The wavelength of the second spectral line in the Balmer series of singly ionized helium atom is