What is the ratio of radii of the orbits corresponding to first excited state and ground state in a hydrogen atom ?

The ratio of radii of the first three Bohr orbits is

What is the value of first excitation energy of hydrogen atom ?

The ratio of radii of second and first Bohr's orbits of H-atom is ___.

Which of the following electronic configuration is not possible in the ground state of an atom?

A set of atoms in an excited state decays

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57V . The threshold frequency of the material is

The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?

State the first law of thermodynamics.

The time period of revolution of electron in its ground state orbit in a hydrogen atom is 1.6 × 10–16 s. The frequency of revolution of the electron in its first excited state (in s–1) is: