Atoms and Nucle...

The ratio of radii of nuclei of two atoms of element of atomic mass numbers 27 and 64 is

The value of Rydberg constant is

The total energy of an electron in 4th orbit of hydrogen atom is

The radius of the orbit of an electron in a hydrogen like atom is 4.5 a_o, where a_o is the Bohr radius. Its orbital angular momentum is 3h/2π. It is given that h is Planck's constant and R is Rydberg's constant. The possible wavelength (λ), when the atom de - excites, is (are)

If R is the Rydberg's constant for hydrogen the wave number of the first line in the Lyman series will be

What is de-Broglie wavelength of electron having energy 10 keV?

A proton is fired from very far away towards a nucleus with charge Q = 120 e, where e is the electronic charge. It makes a closest approach of 10 fm to the nucleus. The de-Broglie wavelength (in units of Fm) of the proton at its start is [take, the proton mass, m_P = (5/3) × 10^-27 kg,
h/e = 4.2 × 10^-15 Js/C,
(1/4πϵ_o) = 9 × 10⁹ m/F, 1 Fm = 10^-15 m]

Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then, the number of spectral lines in the emission spectra will be

Calculate the highest frequency of the emitted photon in the paschen series of spectral lines of the hydrogen atom

The wavelength of the first spectral line in the Balmer series of hydrogen atoms is 6561Å. The wavelength of the second spectral line in Balmer series of singly ionised helium atom is