Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK2025PhysicsAtomic PhysicsActual

If an electron from a hydrogen like atom with Z=2 jumps from the 4^ th orbit to the 2^ nd orbit, it emits a photon of wavelength . What is the wavelength of the photon emitted if an electron jumps from the 5^ th orbit to the 4^ th orbit?

Options

  1. A25 3
  2. B9 25
  3. C16 25
  4. D9 16

Correct answer

A. 25 3

Step-by-step solution

The wavelength of a photon emitted during a transition from orbit n₂ to n₁ in a hydrogen-like atom with atomic number Z is given by the Rydberg formula: 1 = R Z^2 ( 1 n₁^2 - 1 n₂^2 ) For the first case, Z=2 , n₁=2 , and n₂=4 . Substituting these values: 1 = R (2)^2 ( 1 2^2 - 1 4^2 ) = 4R ( 1 4 - 1 16 ) = 4R ( 4-1 16 ) = 4R ( 3 16 ) = 3R 4 Thus, = 4 3R . For the second case, Z=2 , n₁=4 , and n₂=5 . Let the wavelength be ' . 1 ' = R (2)^2 ( 1 4^2 - 1 5^2 ) = 4R ( 1 16 - 1 25 ) = 4R ( 25-16 400 ) = 4R ( 9 400 ) = 9R 1

Practice Atomic Physics on Quantrex Academy →

More from Atomic Physics

What is the frequency of the electron in the first orbit of hydrogen atom of orbital radius 0.5 10⁻¹⁰ m, if its orbital velocity in that orbit is 2.2 10^6 ms⁻¹ . 2026A hydrogen atom absorbs energy and rises to n = 3 state from its ground state n = 1. If the potential energy of the atom at its ground state is -13.6eV, find the wave length emitte 2026An atom with one electron has ionization energy of 24 eV. An electron in this atom makes a transition from an excited energy level, where E = -15 eV, to the ground state. What is t 2026An atom has a single electron. Its ground state energy is -30 eV and its first excited state energy is -8 eV . The atom is bombarded with a stream of photons, each of energy 15 eV 2026The radius of first orbit in hydrogen atom is 5.3 10⁻¹¹ m. The kinetic energy E_K , potential energy E_P and total energy E_T of electron in first orbit are 2026Bohr's second postulate implies quantisation of 2026An electron transition takes place from excited state to ground state in hydrogen atom, then 2026The ratio of the shortest wavelengths of Bracket and Balmer series of hydrogen atom is 2025 Full Atomic Physics list All COMEDK PYQs