The ground state energy of a hydrogen atom is $-13.6 \text{ eV}$. The potential and kinetic energies of the electron in this state are . . . . . . .

Write the formula for the orbital radius of the electron in the atom based on the Bohr atomic model.

The potential energy of an electron in an orbit of a hydrogen atom is $-6.8 \text{ eV}$. The de Broglie wavelength of the electron in this orbit is (where $r_0$ is the Bohr radius).

In a hydrogen atom,an electron of mass $9.1 \times 10^{-31} \ kg$ revolves about a proton in a circular orbit of radius $0.53 \ \mathring{A}$. The radial acceleration and angular velocity of the electron are respectively:

Given below are two statements.
Statement $(I) :$ The dimensions of Planck's constant and angular momentum are same.
Statement $(II) :$ In Bohr's model,electrons revolve around the nucleus only in those orbits for which angular momentum is an integral multiple of Planck's constant.
In the light of the above statements,choose the most appropriate answer from the options given below.

When the electron jumps from a level $n=4$ to $n=1$,the momentum of the recoiled hydrogen atom will be