Advertisements
Advertisements
Question
The longest wavelength doublet absorption transition is observed at 589 and 589.6 nm. Calculate the frequency of each transition and energy difference between two excited states.
Solution
For λ1 = 589 nm
Frequency of transition `("v"_1) = "c"/lambda_1`
`= (3.0xx10^(8) " ms"^(-1))/(589xx10^(-9) " m")`
Frequency of transition (ν1) = 5.093 × 1014 s–1
Similarly, for λ2 = 589.6 nm
Frequency of transition `("v"_2) = "c"/lambda_2`
`= (3.0 xx 10^8 " ms"^(-1))/(589.6xx10^(-9) " m")`
Frequency of transition (ν2) = 5.088 × 1014 s–1
Energy difference (ΔE) between excited states = E1 – E2
Where,
E2 = energy associated with λ2
E1 = energy associated with λ1
ΔE = hν1 – hν2
= h(ν1 – ν2)
= (6.626 × 10-34 Js) (5.093 × 1014 – 5.088 × 1014)s-1
= (6.626 × 10-34 J) (5.0 × 10-3 × 1014)
ΔE = 3.31 × 10-22 J
APPEARS IN
RELATED QUESTIONS
Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit.
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 ?
The electron in hydrogen atom is initially in the third excited state. What is the maximum number of spectral lines which can be emitted when it finally moves to the ground state?
Which of the following parameters are the same for all hydrogen-like atoms and ions in their ground states?
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?
A neutron moving with a speed υ strikes a hydrogen atom in ground state moving towards it with the same speed. Find the minimum speed of the neutron for which inelastic (completely or partially) collision may take place. The mass of neutron = mass of hydrogen = 1.67 × 10−27 kg.v
Radiation from hydrogen discharge tube falls on a cesium plate. Find the maximum possible kinetic energy of the photoelectrons. Work function of cesium is 1.9 eV.
A filter transmits only the radiation of wavelength greater than 440 nm. Radiation from a hydrogen-discharge tube goes through such a filter and is incident on a metal of work function 2.0 eV. Find the stopping potential which can stop the photoelectrons.
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.
The radius of the third Bohr orbit for hydrogen atom is ____________.
If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be ______.
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:
A set of atoms in an excited state decays ______.
An ionised H-molecule consists of an electron and two protons. The protons are separated by a small distance of the order of angstrom. In the ground state ______.
- the electron would not move in circular orbits.
- the energy would be (2)4 times that of a H-atom.
- the electrons, orbit would go around the protons.
- the molecule will soon decay in a proton and a H-atom.
Consider aiming a beam of free electrons towards free protons. When they scatter, an electron and a proton cannot combine to produce a H-atom ______.
- because of energy conservation.
- without simultaneously releasing energy in the from of radiation.
- because of momentum conservation.
- because of angular momentum conservation.
An electron in H-atom makes a transition from n = 3 to n = 1. The recoil momentum of the H-atom will be ______.
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]
How much is the angular momentum of an electron when it is orbiting in the second Bohr orbit of hydrogen atom?
