Which state of triply ionised Beryllium `(Be^(+++))` the same orbital radius as that of the ground state hydrogen ?

Which state of the triply ionized Be^(+++) has the same orbital radius as that of the ground state of hydrogen? Compare the energies of two states.

Which energy state of the triply ionized beryllium (Be^(+++) has the same electron orbital radius as that of the ground state of hydrogen? Given Z for beryllium =4.

Which energy level of C^(5+) ion will have the same energy as that of ground state of hydrogen atom?

Which level of the doubly ionized lithium has the same energy as the ground state energy of the hydrogen atom? Compare the orbital radii of the two levels.

Which of the following orbitals is called the ground state of an H atom?