A quantum of energy is
1.inversely proportional to wavelength of radiation
2.directly proportional to velocity of radiation
3.directly proportional to wavelength of radiation
4.a constant quantity
According to Aufbau principle the 19th electron in an atom goes into the 3d-orbital
1.4s-orbital
2.3d-orbital
3.4p-orbital
4.3p-orbital.
According to Bohrs atomic model
1.Electron in an atom of hydrogen can have only certain values of angular momentum
2.Electrons have particle as well wave character
3.Atomic spectrum of an element should contain only five lines
4.All the above statements are incorrect.
According to de-Broglie
1.a moving proton possesses wave character
2.a moving electron possesses wave character
3.light possess particle character
4.all moving particles possess wave character
An alpha particle consists of
1.two protons and two neutrons
2.two mesons
3.two electrons
4.helium atoms
An atom has 35 nucleons and has atomic number equal to 17. The number of electrons with n = 2 m = 0 in it is
1.2
2.4
3.6
4.3
Avogadros number of helium atoms weigh
1.1.5g
2.3.0g
3.7.0g
4.4.0g
Bohrs concept of the orbit in an atom was contradicted by
1.de Broglie relationship
2.Uncertainty principle
3.Plancks hypothesis
4.Hunds rule
Charge on an electron was shown by
1.J.J. Thomson
2.Mirchoff
3.Ohm
4.M. Planck
Davisson and Germer gave an experimental evidence for
1.wave nature of electron
2.particle nature of electron
3.particle nature of light
4.wave nature of light
Electromagnetic radiation with minimum wavelength is
1.ultra violet
2.radiowaves
3.X-rays
4.infrared
he maximum number of electrons in p-orbital with n = 6 m = 0 is
1.2
2.6
3.10
4.14
he ratio of specific charge of an electron to that of a proton is
1.1:01
2.1837:01:00
3.1.317361111
4.2:01
How many electrons can fit into the sub-shell for which n = 3 and l = 1?
1.16
2.5
3.24
4.6
How many electrons in an atom can have n = 3 l = 2 and m = +2? 10 8 6 2.
1.10
2.8
3.6
4.2
How many electrons in calcium have l = 0?
1.6
2.8
3.10
4.12
In an atom of hydrogen which of the following orbitals has the lowest energy for an electron present in it?
1.3r
2.2p
3.4p
4.2s
In hydrogen atom the energy of an electron is determined by quantum number/s
1.n
2.n and l
3.n l and m
4.n l m and s.
In Lyman series an electron jumps from higher energy level to
1.K energy level
2.M energy level
3.N energy level
4.L energy level
In the case of atomic spectrum of hydrogen which series of lines lie in the visible region?
1.Balmer
2.Paschen
3.Pfund
4.None of these
Mass of positron is the same to that of
1.proton
2.meson
3.electron
4.neutron
Method to determine atomic numbers was devised by `
1.J.J. Thomson
2.H.G..J. Moseley
3.R. Milikan
4.Rutherford.
n a multi-electron atom the energy of the electron in a particular orbital is determined by
1.n only
2.l only
3.n and l
4.n l and m.
Nucleons are
1.protons and electrons
2. electrons and mesons
3.protons electrons and neutrons
4.protons and neutrons
Radial part of the wave function depends on quantum numbers
1.n and s
2.l and m
3.l and s
4.n and l.
Rutherfords model of the atom accounts for the
1.Scattering of alpha particles by metal foils
2.Stability of the electron orbit
3.Stability of the atom
4.Line spectra of light elements.
Subsidiary quantum number of the electron in the outermost shell of Li atom is
1.0
2.1
3.4
4.5
The (n and l) value for 4f orbital is
1.2
2.7
3.8
4.3
The application of quantum mechanics to atomic structure is based largely on the work done by
1.Einstein
2.Germer
3.Schrodinger
4.Davison
The atomic mass of an element is 16.4. It consists of two isotopes having mass number 16 and 18. The ratio of isotopes in the element is:
1.2:01
2.1:02
3.1:04
4.4:01
The atomic mass of an element is 19. The second shell of its atom contains 7 electrons. The number of protons in its nucleus is 13 9 11 8
1.13
2.9
3.11
4.8
The charge to mass ratio of ?-particles is approximately??. The charge to mass ratio of protons
1.twice
2.half
3.four times
4.six times
The element with maximum number of electrons in the valence shell has atomic number
1.15
2.3
3.9
4.2
The exchange of particles considered responsible for keeping the nucleons together are
1.meson
2.electron
3.positron
4.neutron
The false statement about the electron is
1.It has a particle nature
2.It has a dual nature
3.It gives out energy while moving in orbits
4.Its motion is affected by electric field
The filling of electrons in different orbitals of an atom in increasing order of their energy is called
1.Aufbau principle
2.Joules statement
3.Uncertainty principle
4.Paulis exclusion principle
The hydrogen atoms are excited to the stationary state designated by the principal quantum number n = 3. The spectral lines emitted by hydrogen atoms as explained by Bohrs theory will be
1.1
2.2
3.3
4.4
The interrelationship between matter and energy was given by
1.Rutherford
2.Joule
3.de Broglie
4.Einstein
The ionization energy of hydrogen atom is 13.6 eV. The third ionization energy of lithium would be
1.13.6 eV
2.27.2 eV
3.40.8 eV
4.122.4 eV.
The line spectrum observed when electron jumps from higher level into L level is known as
1.Balmer series
2.Pfund series
3.Brackett series
4.Hydrogen series
The maximum number of electrons that can be accommodated by an atom in g?sub-energy level are
1.20
2.25
3.18
4.12
The maximum number of electrons with clockwise spin that can be accommodated in a ?-subshell its
1.14
2.7
3.5
4.10
The maximum number of molecules are in:
1.52 gram of nitrogen peroxide
2.48 gram of ethyl alcohol
3.36 gram of water
4.14 gram of carbon dioxide
The nitrogen atom has 7 protons and 7 electrons. The nitride ion will have
1.7 protons and 7 electrons
2.4 protons and 10 electrons
3.10 protons and 7 electrons
4.10 electrons and 7 protons
The number of electrons with quantum numbers n = 3 and l = 2 in chromium is
1.8
2.6
3.5
4.7
The number of neutrons in the deuterium atom is
1.16
2.3
3.1
4.0
The number of orbitals in the fourth energy level is 4 16 32 9.
1.4
2.16
3.32
4.9
The number of spherical nodes in 3p subshell is
1.Three
2.Two
3.One
4.Zero.
The number of unpaired electrons in the ground state of chromium is
1.1
2.6
3.7
4.2
The number of vacant orbitals in the atom of an element with Z = 14 is 1 6 9 3
1.1
2.6
3.9
4.3
The orbitals with maximum number of possible orientation is: s d f p
1.s
2.d
3.f
4.p
The photoelectric emission of electron from metal surface starts only when the incident light has a certain minimum
1.wavelength
2.velocity
3.frequency
4.acceleration
The quantum number predicting the size as well as the energy of the atomic orbital is:
1.principal quantum number
2.azimuthal quantum number
3.magnetic quantum number
4.spin quantum number
The relationship between energy of a radiation and its frequency was given by
1.Planck
2.Rutherford
3.Einstein
4.Joule
The screening effect of d-electrons is
1.equal to that of f-electron
2.equal to that of d-electron
3.less than that of s-electron
4.more than that of s-electron
The spectra given by the transition of an electron from K level to N level is
1.?rays
2.continuous
3.absorption
4.emission
The statement that the electron occupies available orbital singly before pairing occurs is called
1.Einstein principle
2.Rutherford hypothesis
3.Paulis exclusion principle
4.Hunds rule
The total number of neutrons in dipositive zinc ion with mass number 70 is
1.40
2.48
3.33
4.16
The unrelated member of the following group is
1.He ion
2.neutron
3.proton
4.cyclotron
The velocity of a photon is
1.dependent on its wavelength
2.dependent on its source
3.equal to cube of its amplitude
4.independent of its wavelength
The wavelength of an electron 19.No two electrons in an atom can have the same
1.is equal to that of light
2.remains constant with velocity
3.decreases with an increasing velocity
4.increases with an decreasing velocity
The wavelength of the radio-waves having frequency 3 MHz would be
1.100 m
2.300 m
3.100 nm
4.300 nm.
The yellow colour imparted by sodium to flame is due to
1.the emission of excess of energy in the visible region
2.its sublimation to give yellow vapours
3.its low ionisation energy
4.its photosensitivity
Two electrons occupying the same orbital are distinguished by
1.magnetic quantum number
2.azimuthal quantum number
3.principal quantum number
4.spin quantum number
When an atom is in a magnetic field the possible number of orientations for an orbital of azimuthal quantum number 3 is
1.Three
2.One
3.Five
4.Seven.
When the electron is excited from K level to M level we get
1.??rays
2.cathode rays
3.continuous spectra
4.absorption spectra
Which of the following atoms has a nonspherical outermost orbital.
1.H
2.LI
3.Be
4.B
Which of the following has non-spherical shell of electron? He B Be Li.
1.He
2.B
3.Be
4.Li
Which of the following sub-shells is not permitted? 3f
1.3f
2.4d
3.3s
4.4g.