5.The wave number is the number
1.of waves that cross in one second
2.associated with the orbit
3.of waves per unit length
4.of spectral lines produced
A neutral atom has two electrons in K-shell eight electrons in L-shell and six electrons in M-shell. The total number of s-electrons is
1.2
2.4
3.6
4.8
According to Bohrs atom model the angular momentum of the electron in its non-radiating orbit is in integer multiple of the quantity
1.h/4?
2.h/2?
3.2?/h
4.h/?
According to Rutherford atom model an atom is
1.stable
2.unstable
3.meta stable
4.indivisible
According to Rutherford atom model the electrons are revolving around the nucleus so that centripetal force is provided by
1.gravitational force
2.electrostatic force of attraction between
3.electron and nucleus
4.Van der Walls force
An atom emits a photon when one of its orbital electrons
1.jumps from a higher to a lower energy level
2.jumps from a lower to a higher energy level
3.is removed by the photoelectric effect
4.is at rest
An atom is made up of a number of electrons embedded in a sphere of positive charge. This was proposed by
1.Prout
2.Dalton
3.Thomson
4.Rutherford
For ionizing an excited hydrogen atom the energy required in eV will be
1.a little less than 13.6 eV
2.13.6 eV
3.more than 13.6 eV
4.3.4 eV or loss
In hydrogen atom the radii of the first four electron orbits are in the ratio of
1.1 : 4 : 9 : 25
2.1 : 4 : 9 : 16
3.1 : 2 : 4 : 6
4.1 : 3 : 5 : 7
In the spectral series of hydrogen atom all the lines having their wavelengths in the visible region are called
1.Lyman series
2.Balmer series
3.Paschen series
4.Bracket series
Lines of Paschen series are obtained from the hydrogen atom when the electron jumps from any higher orbit to
1.fourth orbit
2.second orbit
3.third orbit
4.first orbit
Paschen series is in the region of
1.infrared
2.ultraviolet
3.visible
4.far infrared
Plancks constant is equal to
1.6.64 ? 10-34 J/s
2.6.64 ? 10-34 Js
3.6.64 ? 1030 J/s
4.6.64 ? 1034 Js
Prouts suggestion on atomic structure was not accepted because
1.the atomic weights of many elements are equal to multiples of the atomic weight of hydrogen
2.the atomic weights of many elements differed from being multiples of atomic weight of hydrogen
3.the atomic weights of all elements are multiples of the atomic weights of hydrogen
4.the atomic weights of all elements are same irrespective of the atomic weight of hydrogen
The electron in a hydrogen atom makes a transition from an exited state to the ground state. Then (a) its kinetic energy increases (b) its potential energy decreases (c) its angular momentum increases (d) its linear momentum increases. Which of the above statements are correct
1.(a) (b) (c) and (d)
2.(a) (b) and (c) only
3.(a) (b) and (d) only
4.(a) and (b) only
The energy required to remove an electron from the first orbit of hydrogen atom to outside the atom is
1.136 eV
2.1.36 eV
3.13.6 eV
4.0.136 eV
The energy required to remove an electron from the orbit of hydrogen atom is called
1.nuclear force
2.ionization energy
3.potential energy
4.kinetic energy
The energy required to remove an electron from the second orbit of the hydrogen atom is
1.13.60 eV
2.3.40 eV
3.1.51 eV
4.2.00 eV
The ionization potential of hydrogen is 13.6 eV. The energy of an electron in the second orbit is
1.54.4 eV
2.-6.8 eV
3.-27.2 eV
4.-3.4 eV
The lines of Paschen series are obtained for transition of electrons from higher orbits to the orbit quantum number
1.4
2.3
3.2
4.1
The magnitude of the energy of the electron in a hydrogen atom is proportional to (r- radius of the orbit)
1.r
2.1/r
3.r2
4.1/ r2
The nucleus is a sphere of radius about
1.10-11 m
2.10-12 m
3.10-13 m
4.10-14 m
The nucleus of an atom consists of
1.positive charge
2.negative charge
3.both positive and negative charge
4.no charged particles
The potential energy of an electron in a given orbit is
1.equal to its kinetic energy
2.one half of its kinetic energy
3.twice its kinetic energy
4.twice its kinetic energy but negative
The radii of the Bohrs orbit of hydrogen atom are proportional to
1.integer
2.square of integers
3.square root of integers
4.reciprocal of square of integers
The second line of Balmer series in the hydrogen spectrum occurs due to the transition of electrons form the
1.fourth to the third orbit
2.third to the second orbit
3.fourth to the second orbit
4.third to the first orbit
The series of the hydrogen spectral lines given by the expression 1/? = R ? (1/12 � 1/n2) n=2 3 4 � is
1.Balmer series
2.Lyman series
3.Paschen series
4.Pfund series
The total energy of an electron in any atom is
1.zero
2.negative
3.positive
4.infinite
The value of Rydbergs constant is
1.1.094 ? 107 m-1
2.1.094 ? 108 m-1
3.10.94 ? 107 m-1
4.109.4 ? 107 m-1
The wavelength of the spectral lines of the Brackett series of hydrogen atom are in the region
1.visible
2.ultraviolet
3.far infrared
4.infrared
Two electrons in the sub-shell s of shell L are denoted as
1.2s2
2.2s
3.s2
4.2Ls
When the electron of hydrogen atom jumps from any of the outer orbits to the first orbit the series of spectral lines emitted is called
1.Balmer series
2.Paschen series
3.Brackett series
4.Lyman series
When the wavelength of Balmer first line is 6563 � the wavelength of second line is
1.486.1 �
2.4861 �
3.48.61 �
4.4500 �
Which of the following is similar to the solar system
1.Rutherford atom model
2.Dalton atom model
3.Thomson atom model
4.Prout atom model
Which of the following series of hydrogen spectral lines occurs in the ultraviolet region
1.Bracket series
2.Pfund series
3.Balmer series
4.Lyman series