For a hydrogen-like ion of atomic number Z, the energy of the nth leve…

Question

For a hydrogen-like ion of atomic number Z, the energy of the nth level is

Accepted Answer

A. {'text': 'E_n = −13.6 Z² / n² eV', 'label': 'A'}

1. Bohr's formula for one-electron ions: E_n = −13.6 (Z²/n²) eV.
2. Nuclear charge Z increases attraction, deepening the energy well by Z².
3. For He⁺ (Z = 2), n = 1 gives E₁ = −13.6 × 4 = −54.4 eV.
4. The formula assumes a single electron; it fails for multi-electron atoms.
_Source: NCERT Class 11 Chemistry, Ch 2 "Structure of Atom", §2.4_

Answer

{'text': 'E_n = −13.6 Z / n eV', 'label': 'B'}

Answer

{'text': 'E_n = −13.6 / (Z n²) eV', 'label': 'C'}

Answer

{'text': 'E_n = 13.6 Z² × n² eV', 'label': 'D'}