English
Karnataka Board PUCPUC Science Class 11

The Difference in the Frequencies of Series Limit of Lyman Series and Balmer Series is Equal to the Frequency of the First Line of the Lyman Series. Explain.

Advertisements
Advertisements

Question

The difference in the frequencies of series limit of Lyman series and Balmer series is equal to the frequency of the first line of the Lyman series. Explain.

Sum
Advertisements

Solution

The 'series limit' refers to the 'shortest wavelength' (corresponding to the maximum photon energy).

The frequency of the radiation emitted for transition from n1 to n2  is given by

`f = k (1/n_1^2 - 1/n_2^2)`

Here, k is a constant.

For the series limit of Lyman series,

`n_1 = 1`

`n_2 = ∞`

Frequency, `f_1 = k( 1/1^2 - 1/∞ ) = k`

For the first line of Lyman series,

`n_1 = 1`

`n_2 = 2`

Frequency, `f_2 = k(1/1^2 - 1/2^2) = (3k)/4`

For series limit of Balmer series,

`n_1 = 2`

`n_2 = ∞ `

`f_1 = k(1/2^2 - 1 /∞) = k/4`

`f_1 - f_3 = f_2`

Thus, the difference in the frequencies of series limit of Lyman series and Balmer series is equal to the frequency of the first line of the Lyman series.

shaalaa.com
  Is there an error in this question or solution?
Chapter 21: Bohr’s Model and Physics of Atom - Short Answers [Page 383]

APPEARS IN

HC Verma Concepts of Physics Vol. 2 [English] Class 11 and 12
Chapter 21 Bohr’s Model and Physics of Atom
Short Answers | Q 7 | Page 383

RELATED QUESTIONS

An electron is orbiting in 5th Bohr orbit. Calculate ionisation energy for this atom, if the ground state energy is -13.6 eV.


What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?


What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is –2.18 × 10–11 ergs.


Explain, giving reasons, which of the following sets of quantum numbers are not possible.

  1. n = 0, l = 0, ml = 0, ms = + ½
  2. n = 1, l = 0, ml = 0, ms = – ½
  3. n = 1, l = 1, ml = 0, ms = + ½
  4. n = 2, l = 1, ml = 0, ms = – ½
  5. n = 3, l = 3, ml = –3, ms = + ½
  6. n = 3, l = 1, ml = 0, ms = + ½

How many electrons in an atom may have the following quantum numbers?

n = 4, `m_s =  -1/2`


The gravitational attraction between electron and proton in a hydrogen atom is weaker than the Coulomb attraction by a factor of about 10−40. An alternative way of looking at this fact is to estimate the radius of the first Bohr orbit of a hydrogen atom if the electron and proton were bound by gravitational attraction. You will find the answer interesting.


Using Bohr's postulates, derive the expression for the orbital period of the electron moving in the nth orbit of hydrogen atom ?


Using Bohr’s postulates, obtain the expressions for (i) kinetic energy and (ii) potential energy of the electron in stationary state of hydrogen atom.

Draw the energy level diagram showing how the transitions between energy levels result in the appearance of Lymann Series.


A positive ion having just one electron ejects it if a photon of wavelength 228 Å or less is absorbed by it. Identify the ion.


Radiation coming from transition n = 2 to n = 1 of hydrogen atoms falls on helium ions in n = 1 and n = 2 states. What are the possible transitions of helium ions as they absorbs energy from the radiation?


Light from Balmer series of hydrogen is able to eject photoelectrons from a metal. What can be the maximum work function of the metal?


In which of the following systems will the wavelength corresponding to n = 2 to n = 1 be minimum?


Consider two different hydrogen atoms. The electron in each atom is in an excited state. Is it possible for the electrons to have different energies but same orbital angular momentum according to the Bohr model? Justify your answer.


According to Bhor' s theory the moment of momentum of an electron revolving in second orbit of hydrogen atom will be.


A hydrogen atom in its first excited state absorbs a photon of energy x × 10-2 eV and exited to a higher energy state where the potential energy of electron is -1.08 eV. The value of x is ______.


According to Bohr atom model, in which of the following transitions will the frequency be maximum?


The energy required to remove the electron from a singly ionized Helium atom is 2.2 times the energy required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is ______. 


Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength λ. If R is the Rydberg constant then the principal quantum number n of the excited state is ______.


The wavelength of the second line of the Balmer series in the hydrogen spectrum is 4861 Å. Calculate the wavelength of the first line of the same series.


The de Broglie wavelength of an electron in the first Bohr’s orbit of hydrogen atom is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×