Quiz for Bohr’s model

Q1: Who proposed the Bohr model of the atom?

A. Rutherford B. Bohr C. Thomson D. Einstein

Q2: According to Bohr model, electrons revolve around nucleus in:

A. Any orbit B. Fixed energy orbits C. Random paths D. Stationary position

Q3: The energy of electron in nth orbit is given by:

A. E_n = -13.6/n² eV B. E_n = 13.6n² eV C. E_n = 13.6/n eV D. E_n = -13.6n eV

Q4: Radius of nth orbit in hydrogen atom is:

A. r_n = n² × 0.53 Å B. r_n = n × 0.53 Å C. r_n = 0.53/n Å D. r_n = 0.53/n² Å

Q5: The smallest radius in Bohr model is called:

A. Bohr radius B. Electron radius C. Nuclear radius D. Atomic radius

Q6: Energy difference between two orbits corresponds to:

A. Frequency of emitted photon B. Speed of electron C. Radius of orbit D. Mass of atom

Q7: Bohr’s quantization condition is based on:

A. Angular momentum quantization B. Energy conservation C. Electrostatic force D. Speed of light

Q8: What is the energy of electron in second orbit (n=2)?

A. -3.4 eV B. -13.6 eV C. -6.8 eV D. -1.5 eV

Q9: The frequency of radiation emitted during electron transition is:

A. f = ΔE/h B. f = h/ΔE C. f = ΔE × h D. f = ΔE

Q10: Bohr’s model successfully explained:

A. Atomic spectra of hydrogen B. Molecular bonding C. Radioactive decay D. Electron spin

Q11: The angular momentum of electron in nth orbit is:

A. mvr = nh/2π B. mvr = h/n C. mvr = h D. mvr = 2πnh

Q12: Bohr’s radius is approximately:

A. 0.53 Å B. 1 Å C. 0.1 Å D. 10 Å

Q13: In Bohr’s model, the speed of electron in first orbit is about:

A. 2.2 × 10⁶ m/s B. 3 × 10⁸ m/s C. 1 × 10⁵ m/s D. 5 × 10⁶ m/s

Q14: Which constant is fundamental in Bohr’s model?

A. Planck’s constant B. Gravitational constant C. Boltzmann constant D. Speed of light

Q15: The energy emitted or absorbed is:

A. Difference of energies of two orbits B. Sum of energies C. Product of energies D. None

Q16: Limitations of Bohr model include:

A. Only explains hydrogen atom B. Explains all atoms C. Does not involve quantum D. No limitations

Q17: Bohr’s theory introduced the idea of:

A. Quantized energy levels B. Continuous energy levels C. No electrons D. Classical orbits

Q18: Bohr’s postulate states:

A. Electron does not radiate energy in stable orbit B. Electron emits energy continuously C. Electron is static D. Electron follows elliptical orbit

Q19: When electron jumps from higher to lower orbit:

A. Photon is emitted B. Photon is absorbed C. Energy is lost as heat D. Nothing happens

Q20: The spectral lines of hydrogen are explained by:

A. Bohr model B. Newton’s laws C. Maxwell’s equations D. Archimedes principle