Rydberg is — Atomic Structure Chemistry Question

💡 Solution & Explanation

Distinguish Rydberg (unit) from Rydberg constant ($R_\infty=1.097\times10^7$ m$^{-1}$). 1 Rydberg = $hcR_\infty = (6.626\times10^{-34})(3\times10^8)(1.097\times10^7)$$=2.18\times10^{-18}$ J $=13.6$ eV. It equals the ionisation energy of H from ground state. Correct: (D) unit of energy, 1 Ry = 13.6 eV. $\boxed{D}$