Imagine removing one electron from `He^(4)` and `He^(3)`. Their energy levels, as worked out on the basis of Bohr model will be very close. Explain why ?

Explanation

Here `""_(2)He^(3) and ""_(2)He^(4` are isotopes of helium. When one electron is removed from each of them, they both behave like H-atom with single electron. Electrons in them have same orbital radii as per the formula `r_(n)=(epsi_(0)n^(2)h^(2))/(pi m Ze^(2))` and hence their energy levels are also obtained very close to each other.