Advertisements
Advertisements
प्रश्न
The ground state energy of hydrogen atoms is -13.6 eV. The photon emitted during the transition of electron from n = 3 to n = 1 unknown work function. The photoelectrons are emitted from the material with a maximum kinetic energy of 9 eV. Calculate the threshold wavelength of the material used.
Advertisements
उत्तर
For a transition from n = 3 to n = 1 state, the energy of the emitted photon,
hv = E2 – E1 = `13.6[1/1^2 - 1/3^2]` eV = 12.1 eV.
From Einstein’s photoelectric equation,
hv + Kmax + W0
∴ W0 = hv – Kmax = 12.1 – 9 = 3.1 eV
Threshold wavelength,
λth = `("hc")/"W"_0`
= `(6.62 xx 10^-34 xx 3 xx 10^8)/(3.1 xx 1.6 xx 10^-19)`
= 4 × 10–7m
APPEARS IN
संबंधित प्रश्न
If the velocity of the electron in Bohr’s first orbit is 2.19 × 106 ms-1, calculate the de Broglie wavelength associated with it.
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
According to Bohr, 'Angular momentum of an orbiting electron is quantized'. What is meant by this statement?
If l3 and l2 represent angular momenta of an orbiting electron in III and II Bohr orbits respectively, then l3: l2 is :
Using Bohr's postulates derive the expression for the radius of nth orbit of the electron.
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?
The Bohr model for the spectra of a H-atom ______.
- will not be applicable to hydrogen in the molecular from.
- will not be applicable as it is for a He-atom.
- is valid only at room temperature.
- predicts continuous as well as discrete spectral lines.
The line at 434 nm in the Balmer series of the hydrogen spectrum corresponds to a transition of an electron from the nth to second Bohr orbit. The value of n is ______.
A 100 eV electron collides with a stationary helium ion (He+) in its ground state and exits to a higher level. After the collision, He+ ions emit two photons in succession with wavelengths 1085 Å and 304 Å. The energy of the electron after the collision will be ______ eV.
Given h = 6.63 × 10-34 Js.
Calculate the radius of the second orbit of He+.
