The electrons are more likely to be found:
in the region a and c
in the region a and b
only in the region a
only in the region c
The graph between and r ( radial distance ) is shown below.
This represents :
3s orbital
2s orbital
1s orbital
2p orbital
Among the following, the energy of 2s orbital is lowest in:
K
H
Li
Na
The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about . The spectral series are :
Lymen and Paschen
Balmer and Brackett
Brackett and Pfund
Paschen and Pfund
Which one of the following about an electron occupying the 1s orbitals in a hydrogen atom is incorrect ? ( The Bohr radius is represented by )
The probability density of finding the electron is maximum at the nucleus.
The electron can be found at a distance from the nucleus.
The magnitude of the potential energy is double that of its kinetic energy on an average .
The total energy of the electron is maximum when it is at a distance from the nucleus.
For any given series of spectral lines of atomic hydrogen, let be the difference in maximum and minimum frequencies in
The ratio is :
If P is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength , then for 1.5 p momentum of the photoelectron, the wavelength of the light should be:
(Assume kinetic energy of elected photoelectron to be very high in comparison to work function):
The quantum number of four electrons are given below:
The correct order of their increasing energies will be :
8
6
4
2
8 in oxygen and two electrons in hydrogen
Heat treatment of muscular pain involves radiation of wavelength of about 900 nm . Which spectral line of H-atom is suitable for this purpose ?
Paschen ,
The de Broglie wavelength () associated with a photoelectron varies with the frequency (v) of the incident radiation as, [v_{0} is threshold frequency] :
If the de Broglie wavelength of the electron in n ^{th} Bohr orbit in a hydrogenic atom is equal to 1.5 (a_{0} is Bohr radius), then the value of n/z is :
0.75
1.0
1.50
0.40
THe 71^{s} electron of an element X with an atomic number of 71 enters into the orbital:
6p
5d
4f
6s
Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface ?
L = 2 means d orbitals
electronic configuration of Fe2+ = [Ar] 3d6
six electrons in d orbitals 4 will be unpaired 2 will be paired
electronic configuration of Co2+ = [Ar] 3d7
three electrons will be unpaired four will be paired
electronic configuration of Ni2+ = [Ar] 3d8
two electrons will be unpaired and six will be paired
So the sum of paired electrons is 2+4+6=12.
The ground state energy of hydrogen atom is 13.6 eV. The energy of second excited state of ion in eV is:
-54.4
-3.4
-27.2
-6.04
What is the work function of the metal if the light of wavelength generates photoelectrons of velocity from it ?
(Mass of electron =
Velocity of light =
Planck's constant =
Charge of electron = )
0.9eV
3.1eV
2.1eV
4.0eV