Consider one He⁺ ion in an excited state (n = 5). Which of the following observations will hold true as per Bohr's model?
Correct answer: D. The electronic separation from the center of the nucleus is more than 6Å
- A. 10 emission spectral lines will be seen
- B. The ionization energy needed is less than 2 eV
- C. The longest emitted wavelength is less than 10/R (R = Rydberg's constant)
- D. The electronic separation from the center of the nucleus is more than 6Å
Explanation
The radius of the orbit is calculated by r = a₀(n²/Z), where a₀ ≈ 0.529 Å. For a He⁺ ion (Z=2) in the n=5 state, the radius is r = 0.529 × (5²/2) = 6.61 Å. This value is greater than 6 Å. Option A can also be considered along with option D.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Atomic Structure
Atomic structure covers the discovery of the proton, Planck's quantum theory, hydrogen emission spectra and the evidence for quantized energy levels. You will use quantum numbers to describe orbitals, distinguish s, p, d and f orbital shapes, and write electronic configurations, including the correct order of electron filling.
Practise Atomic Structure
922 free Atomic Structure MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Atomic Structure questions
In a single hydrogen atom, the electron is excited to its 6th orbit. The maximum number of distinct spectral lines possible when it comes to the ground state is
An electron is allowed to move freely in a closed cubic box of length 10 cm. The minimum uncertainty in its velocity will be observed as:
If a dye absorbs a photon of wavelength λ and re-emits the absorbed energy into two photons of wavelengths λ₁ and λ₂ respectively, then:
The total number of electrons in Cu²⁺ for which the summation of the azimuthal quantum number (l) and magnetic quantum number (m) is zero is:
Photons having energy equivalent to the binding energy of the 4th state of a He⁺ ion are used on a metal surface with a work function of 1.4 eV. If electrons are further accelerated through a potential difference of 4V, the minimum de-Broglie wavelength associated with the electron is:
If Rutherford had used β⁻ particles instead of α-particles in his gold-leaf experiment, which observation from the original experiment would not occur?