Moderate

The speed of electron in the first Bohr orbit is:

Correct answer: A. 2.19 x 10^6 ms-1

  • A. 2.19 x 10^6 ms-1
  • B. 2.19x 10- 6 ms- 1
  • C. 2.19 x 10^4 ms-1
  • D. 2.19 x 10^-4 ms-1

Explanation

According to Bohr's model of the hydrogen atom, the speed of an electron in the first Bohr orbit can be calculated using the formula: v = Ze² / 2εοh Where, Atomic number = Z = 1 Charge = e = 1.602 × 10-19 C Permittivity of free space = εο =8.854×10-12 C²/Nm² Planck's constant = h = 6.626 × 10-34 J's Putting the values in the above formula, we get: v = 1 × (1.602 × 10-19)² / 2 × (8.854×10-12) × (6.626 × 10-34) v = 2.19 × 106 ms-1

Last updated

About Atomic Spectra

Atoms emit or absorb light at specific wavelengths because electrons occupy quantized energy levels and change levels by absorbing or releasing photons. The topic covers emission and absorption spectra, spectral series, hydrogen’s line spectrum, energy-level transitions, and the relation between wavelength, frequency and photon energy.

Practise Atomic Spectra

356 free Atomic Spectra MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Physics questions like this

Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions