The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are :

The graph between $${\left| \psi \right|^2}$$ and r (radial distance) is shown below. This represents :

The isoelectronic set of ions is :

Which one of the following about an electron occupying the 1s orbital in a hydrogen atom is incorrect ?

(The Bohr radius is represented by a₀)