Exams › NEET › Physics

The energy of hydrogen atom in nth orbit is Eₙ, then the energy in nth orbit of single ionised helium atom will be

1. 4Eₙ
2. Eₙ / 4
3. 2Eₙ
4. Eₙ / 2

Correct answer: 4Eₙ

Solution

The energy of an electron in an orbit is proportional to the square of the atomic number (Z²). For a single ionized helium atom (Z=2), the energy will be 4 times that of a hydrogen atom (Z=1) in the same orbit.

Related NEET Physics questions

• The ground state energy of H-atom 13.6 eV. The energy needed to ionize H-atom from its second excited state.
• To explain his theory, Bohr used
• The ionisation energy of hydrogen atom is 13.6 eV, the ionisation energy of helium atom would be
• For the wavelength λ = 975 Å, calculate the number of spectral lines emitted when an electron transitions from n = 4 to n = 1.
• The ratio of temperatures T₁/T₂ is proportional to the cube of the ratio of principal quantum numbers n₁/n₂. If n₁ = 2n₂, find the ratio T₁/T₂.
• According to the Rydberg formula, calculate the wavelength λ₁ for the transition from n = 4 to n = 3.

⚔️ Practice NEET Physics free + battle 1v1 →