Advertisements
Advertisements
प्रश्न
What is the shortest wavelength present in the Paschen series of spectral lines?
Advertisements
उत्तर
Rydberg’s formula is given as:
` "hc"/lambda = 21.76 xx 10^(-19) [1/"n"_1^2 - 1/"n"_2^2]`
Where,
h = Planck’s constant = 6.6 × 10−34 Js
c = Speed of light = 3 × 108 m/s
(n1 and n2 are integers)
The shortest wavelength present in the Paschen series of the spectral lines is given for values n1 = 3 and n2 = ∞.
`"hc"/lambda = 21.76 xx 10^(-19) [1/(3)^2 - 1/(∞)^2]`
`lambda = (6.6 xx 10^(-34) xx 3 xx 10^8 xx 9)/(21.76 xx 10^(-19)`
= 8.189 × 10−7 m
= 818.9 nm
संबंधित प्रश्न
An electron jumps from fourth to first orbit in an atom. How many maximum number of spectral lines can be emitted by the atom? To which series these lines correspond?
Determine the series limit of Balmer, Paschen, and Pfund series, given the limit for Lyman series is 912 Å.
In the figure below, D and E respectively represent

Which of the following is TRUE?
Let the series limit for Balmer series be 'λ1' and the longest wavelength for Brackett series be 'λ2'. Then λ1 and λ2 are related as ______.
The energy (in eV) required to excite an electron from n = 2 to n = 4 state in hydrogen atom is ____________.
In hydrogen atom, the product of the angular momentum and the linear momentum of the electron is proportional to (n = principal quantum number) ____________.
The radii of the first four Bohr orbits of hydrogen atom are related as ____________.
An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. What is the wave number of the emitted radiations? (R = Rydberg's constant)
What is the minimum energy that must be given to a H atom in ground state so that it can emit an Hγ line in Balmer series. If the angular momentum of the system is conserved, what would be the angular momentum of such Hγ photon?
Deutrium was discovered in 1932 by Harold Urey by measuring the small change in wavelength for a particular transition in 1H and 2H. This is because, the wavelength of transition depend to a certain extent on the nuclear mass. If nuclear motion is taken into account then the electrons and nucleus revolve around their common centre of mass. Such a system is equivalent to a single particle with a reduced mass µ, revolving around the nucleus at a distance equal to the electron-nucleus separation. Here µ = meM/(me + M) where M is the nuclear mass and m e is the electronic mass. Estimate the percentage difference in wavelength for the 1st line of the Lyman series in 1H and 2H. (Mass of 1H nucleus is 1.6725 × 10–27 kg, Mass of 2H nucleus is 3.3374 × 10–27 kg, Mass of electron = 9.109 × 10–31 kg.)
Determine the shortest wavelengths of Balmer and Pasch en series. Given the limit for the Lyman series is 912 Å.
The first three spectral lines of H-atom in the Balmer series are given λ1, λ2, λ3 considering the Bohr atomic model, the wavelengths of the first and third spectral lines `(lambda_1/lambda_3)` are related by a factor of approximately 'x' × 10–1. The value of x, to the nearest integer, is ______.
The frequencies for series limit of Balmer and Paschen series respectively are 'v1' and 'v3'. If frequency of first line of Balmer series is 'v2' then the relation between 'v1', 'v2' and 'v3' is ______.
In the hydrogen atoms, the transition from the state n = 6 to n = 1 results in ultraviolet radiation. Infrared radiation will be obtained in the transition.
Calculate the wavelength of the first two lines in the Balmer series of hydrogen atoms.
