NEET Atoms and Nuclei — Set 2

Question 1

What is the total energy of an electron in the $ n = 2 $ state of a hydrogen atom? (Use $ E_n = -\frac{13.6}{n^2} \, \text{eV} $)

Accepted Answer

$ E_2 = -\frac{13.6}{2^2} = -\frac{13.6}{4} = -3.4 \, \text{eV} $.

Question 2

What is the significance of the negative total energy of an electron in a hydrogen atom according to Bohr’s model?

Accepted Answer

The negative total energy indicates that the electron is bound to the nucleus, requiring energy to be supplied to free it.

Question 3

A hydrogen atom is excited to the $ n = 4 $ state and returns to the ground state. What is the maximum energy of the emitted photon? (Use $ E_n = -\frac{13.6}{n^2} \, \text{eV} $)

Accepted Answer

$ E_4 = -0.85 \, \text{eV} $, $ E_1 = -13.6 \, \text{eV} $. $ \Delta E = -0.85 - (-13.6) = 12.75 \, \text{eV} $.

NEET Physics: Atoms and Nuclei — Practice Set 2

Q1. What is the total energy of an electron in the \( n = 2 \) state of a hydrogen atom? (Use \( E_n = -\frac{13.6}{n^2} \, \text{eV} \))

Q2. What is the significance of the negative total energy of an electron in a hydrogen atom according to Bohr’s model?

Q3. A hydrogen atom is excited to the \( n = 4 \) state and returns to the ground state. What is the maximum energy of the emitted photon? (Use \( E_n = -\frac{13.6}{n^2} \, \text{eV} \))

Q4. What is the energy required to excite a hydrogen atom from \( n = 1 \) to \( n = 3 \)? (Use \( E_n = -\frac{13.6}{n^2} \, \text{eV} \))

Q5. In Rutherford’s scattering experiment, what happens to an alpha-particle with a large impact parameter?

Q6. An electron in a hydrogen atom has an angular momentum of \( 1.05 \times 10^{-34} \, \text{J·s} \). What is its principal quantum number? (Use \( h = 6.6 \times 10^{-34} \, \text{J·s} \))

Q7. Which of the following statements is correct about the Bohr model’s prediction of hydrogen spectra?

Q8. An electron beam of 11.0 eV excites a hydrogen atom in the ground state. What is the highest energy level reached? (Use \( E_n = -\frac{13.6}{n^2} \, \text{eV} \))

Q9. In a hydrogen atom, the radius of the first orbit is \( 5.3 \times 10^{-11} \, \text{m} \). What is the circumference of the third orbit?

Q10. What is the ratio of the radius of the \( n = 4 \) orbit to the \( n = 2 \) orbit in a hydrogen atom?