NEET Atoms and Nuclei — Set 7

Question 1

Why does the Bohr model predict discrete spectral lines for hydrogen?

Accepted Answer

Discrete spectral lines arise because electrons transition between fixed energy levels, emitting photons with energies equal to the differences between these levels.

Question 2

What is the energy required to ionize a hydrogen atom from its ground state? (Ground state energy = -13.6 eV)

Accepted Answer

Ionization energy = energy to reach $ E = 0 $ from ground state. $ E_1 = -13.6 \, \text{eV} $, $ E_\infty = 0 \, \text{eV} $. Energy required = $ 0 - (-13.6) = 13.6 \, \text{eV} $.

Question 3

What is the primary reason Rutherford’s model could not explain the line spectra of atoms?

Accepted Answer

Rutherford’s model lacks quantized energy levels, predicting continuous radiation as electrons accelerate, not discrete spectral lines.

NEET Physics: Atoms and Nuclei — Practice Set 7

Q1. Why does the Bohr model predict discrete spectral lines for hydrogen?

Q2. What is the energy required to ionize a hydrogen atom from its ground state? (Ground state energy = -13.6 eV)

Q3. What is the primary reason Rutherford’s model could not explain the line spectra of atoms?

Q4. A hydrogen atom in the ground state is bombarded with a 12.5 eV electron beam. What is the maximum energy level the electron can reach? (Use \( E_n = -\frac{13.6}{n^2} \, \text{eV} \))

Q5. In a hydrogen atom, the total energy of an electron in the ground state is -13.6 eV. What is the magnitude of its potential energy?

Q6. What does the presence of discrete wavelengths in the hydrogen spectrum indicate?

Q7. In Rutherford’s experiment, what does the scattering of alpha-particles at small angles indicate?

Q8. In Bohr’s model, what prevents an electron from emitting radiant energy while revolving in a stable orbit?

Q9. Which of the following statements is correct about the ionization energy of a hydrogen atom in Bohr’s model?

Q10. In Rutherford’s scattering experiment, what does a small fraction of alpha-particles rebounding back indicate?