Advertisements
Advertisements
प्रश्न
Show that the first few frequencies of light that is emitted when electrons fall to the nth level from levels higher than n, are approximate harmonics (i.e. in the ratio 1 : 2 : 3...) when n >> 1.
Advertisements
उत्तर
`v_(mn) = cRZ^2 [1/(n + p)^2 - 1/n^2]`, where m = n + p, (p = 1, 2, 3, ...) and R is Rydberg constant.
For p << n.
`v_(mn) = cRZ^2 [1/n^2 (1 + p/n)^-2 - 1/n^2]`
`v_(mn) = cRZ^2 [1/n^2 - (2p)/n^3 - 1/n^2]`
`v_(mn) = cRZ^2 (2p)/n^3 ≃ ((2cRZ^2)/n^3)p`
Thus, νmn are approximately in the order 1, 2, 3...........
APPEARS IN
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.
Which of the following transition will have highest emission wavelength?
Which of the following is TRUE?
Let v1 and v3 be the frequency for series limit of Balmer and Paschen series respectively. If the frequency of first line of Balmer series is v2 then, relation between v1 and v2 and v3 is ____________.
In hydrogen spectrum, which of the following spectral series lies in ultraviolet region?
The radii of the first four Bohr orbits of hydrogen atom are related as ____________.
If the mass of the electron is reduced to half, the Rydberg constant ______.
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)
To produce an emission spectrum of hydrogen it needs to be ______.
The first four spectral lines in the Lyman series of a H-atom are λ = 1218 Å, 1028Å, 974.3 Å and 951.4 Å. If instead of Hydrogen, we consider Deuterium, calculate the shift in the wavelength of these lines.
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.
Determine the series limit of Balmer, Paschen and Brackett series, given the limit for Lyman series is 911.6 Å.
Find the wavelength and wave number of the first member of the Balmer series in Hydrogen spectrum. (`R =1.097xx10^7m^(-1)`)
The de-Broglie wavelength of the electron in the hydrogen atom is proportional to ______.
