Advertisements
Advertisements
प्रश्न
Draw a neat, labelled energy level diagram for H atom showing the transitions. Explain the series of spectral lines for H atom, whose fixed inner orbit numbers are 3 and 4 respectively.
Advertisements
उत्तर
Paschen series:
i. The spectral lines of this series correspond to the transition of an electron from some higher energy state to 3rd orbit.
ii. For paschen series, p = 3 and n = 4, 5,...
The wave numbers and the wavelengths of the spectral lines constituting the Paschen series are given by,
`barv=1/lambda=R(1/3^2-1/n^2)`
iii. Paschen series lies in the infrared region of the spectrum which is invisible and contains infinite number of lines.
iv. Wavelengths for n = 4 and 5 are 18750 Å and 12820 Å respectively.
Brackett series:
i. The spectral lines of this series corresponds to the transition of an electron from a higher energy state to the 4th orbit.
ii. For this series, p = 4 and n = 5, 6, 7,...
The wave numbers and the wavelengths of the spectral lines constituting the Brackett series are given by,
`barv=1/lambda=R(1/4^2-1/n^2)`
iii. This series lies in the ne ar infrared region of the spectrum and contains infinite number of lines. Wavelengths for n = 5 and 6, are 40518 Å and 26253 Å respectively
APPEARS IN
संबंधित प्रश्न
How many electrons in an atom may have the following quantum numbers?
n = 3, l = 0
Calculate the energy required for the process
\[\ce{He^+_{(g)} -> He^{2+}_{(g)} + e^-}\]
The ionization energy for the H atom in the ground state is 2.18 ×10–18 J atom–1
State Bohr postulate of hydrogen atom that gives the relationship for the frequency of emitted photon in a transition.
Which of the following parameters are the same for all hydrogen-like atoms and ions in their ground states?
When a photon stimulates the emission of another photon, the two photons have
(a) same energy
(b) same direction
(c) same phase
(d) same wavelength
Consider a neutron and an electron bound to each other due to gravitational force. Assuming Bohr's quantization rule for angular momentum to be valid in this case, derive an expression for the energy of the neutron-electron system.
Suppose in an imaginary world the angular momentum is quantized to be even integral multiples of h/2π. What is the longest possible wavelength emitted by hydrogen atoms in visible range in such a world according to Bohr's model?
Calculate angular momentum of an electron in the third Bohr orbit of a hydrogen atom.
The dissociation constant of a weak base (BOH) is 1.8 × 10−5. Its degree of dissociation in 0.001 M solution is ____________.
A particle has a mass of 0.002 kg and uncertainty in its velocity is 9.2 × 10−6 m/s, then uncertainty in position is ≥ ____________.
(h = 6.6 × 10−34 J s)
For an electron in the second orbit of hydrogen, what is the moment of momentum as per the Bohr's model?
In Bohr model of hydrogen atom, which of the following is quantised?
If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be ______.
Ratio of longest to shortest wavelength in Balmer series is ______.
Hydrogen atom has only one electron, so mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?
Derive an expression for the frequency of radiation emitted when a hydrogen atom de-excites from level n to level (n – 1). Also show that for large values of n, this frequency equals to classical frequency of revolution of an electron.
According to the Bohr theory of H-atom, the speed of the electron, its energy and the radius of its orbit varies with the principal quantum number n, respectively, as:
For the ground state, the electron in the H-atom has an angular momentum = h, according to the simple Bohr model. Angular momentum is a vector and hence there will be infinitely many orbits with the vector pointing in all possible directions. In actuality, this is not true ______.
The mass of a H-atom is less than the sum of the masses of a proton and electron. Why is this?
The radius of the innermost electron orbit of a hydrogen atom is 5.3 × 10–11m. The radius of the n = 3 orbit is ______.
A hydrogen atom in is ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen atom will increase by the value of ______.
(Given, Planck's constant = 6.6 × 10-34 Js)
What is the energy associated with first orbit of Li2+ (RH = 2.18 × 10-18)?
In hydrogen atom, transition from the state n = 6 to n = 1 results in ultraviolet radiation. Infrared radiation will be obtained in the transition ______.
A 20% efficient bulb emits light of wavelength 4000 Å. If the power of the bulb is 1 W, the number of photons emitted per second is ______.
[Take, h = 6.6 × 10-34 J-s]
What is the energy of an electron in stationary state corresponding to n = 2?
Write the ionisation energy value for the hydrogen atom.
State three postulates of Bohr's theory of hydrogen atom.
The energy of an electron in the nth orbit of the hydrogen atom is En = -13.6/n2eV. The negative sign of energy indicates that ______.
How much is the angular momentum of an electron when it is orbiting in the second Bohr orbit of hydrogen atom?
The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li2+ ion (atomic number = 3) in a similar state is ______.
