6.For ionizing an excited hydrogen atom, the energy required in eV will be

7.Which of the following is similar to the solar system

8.When the electron of hydrogen atom jumps from any of the outer orbits to the first orbit, the series of spectral lines emitted is called

9.The nucleus is a sphere of radius about

10.According to Bohr’s atom model, the angular momentum of the electron in its non-radiating orbit is in integer multiple of the quantity