The species having identical radii according to the Bohr's theory are :

A. H (first orbit)

B. $\mathrm{He}^{+}$(first orbit)

C. $\mathrm{He}^{+}$(Second orbit)

D. $\mathrm{Li}^{2+}$ (first orbit)

E. $\mathrm{Be}^{3+}$ (Second orbit)

Choose the correct answer from the options given below :

What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

Which of the following is correct set of 4 quantum numbers of $19^{\text {th }}$ electron in Chromium (Atomic number $=24$ ) in accordance with Aufbau principle?

What is the energy (in J atom⁻¹) required for the following process?

Li²⁺ (g) → Li³⁺ (g) + e⁻

(Take the ionization energy for the H atom in the ground state as $2.18 \times 10^{−18} \text{ J atom}^{−1}$)