The ionisation energy of $10$ times ionised sodium atom is:

If an electron in a hydrogen atom jumps from the third orbit to the second orbit,the frequency of the emitted radiation is given by (where $c$ is the speed of light and $R$ is the Rydberg constant):

Which of the following relations is correct between the time period $(T)$ and the number of orbits $(n)$ for an electron revolving in a Bohr orbit?

The orbital acceleration of an electron in a hydrogen-like atom is given by:

The ground state energy of a hydrogen atom is $-13.6 \text{ eV}$. What is the ratio of the kinetic energy to the potential energy of the electron in this state?

The de Broglie wavelength of an electron in the first orbit of Bohr's model is . . . . . . .