-
Calculate the number of protons, neutrons and electrons in\[_{35}^{80}Br\].
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Number of electrons, protons and neutrons in a species are
equal to 18, 16 and 16 respectively. Assign the proper symbol to the species.
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The Vividh Bharati Station of All India Radio, Delhi
broadcasts on a frequency 1.368 kHz. (kilohertz). Calculate the wavelength of
the electromagnetic radiation emitted by the transmitter. Which part of the
electromagnetic spectrum does it belong to?
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The wavelength range of visible spectrum extends from 400 nm
to 750 nm. Express the frequency of the radiations in (\[Hz\]).
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Calculate: (a) wave number and (b) frequency
of a yellow radiation having wavelength 5800 A.
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-
Calculate energy of one mole of photons of radiation whose
frequency is \[5\times {{10}^{14}}Hz.\]
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A 100 watt bulb emits monochromatic light of wavelength 400
nm. Calculate the number of photons emitted per second by the bulb.
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When the electromagnetic radiation of wavelength
300 nm falls on the surface of sodium, electrons are emitted with a kinetic energy
\[1.68\times {{10}^{5}}J\,mo{{l}^{-1}}\]. What is the minimum energy needed to
remove an electron from sodium?
What is the maximum wavelength that will cause a
photoelectron to be emitted?
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When the electromagnetic radiation of wavelength
300 nm falls on the surface of sodium, electrons are emitted with a kinetic energy
\[1.68\times {{10}^{5}}J\,mo{{l}^{-1}}\]. What is the minimum energy needed to
remove an electron from sodium?
What is the maximum wavelength that will cause a
photoelectron to be emitted?
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The threshold frequency \[{{v}_{0}}\] for a metal is\[7\times
{{10}^{14}}{{\sec }^{-1}}\]. Calculate the kinetic energy of an electron
emitted when radiation of frequency \[v=1\times {{10}^{15}}{{\sec }^{-1}}\]
hits the metal.
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What are the frequency and wavelength of a photon emitted
during a transition from n = 5 to the n = 2 state in the hydrogen atom?
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Calculate the energy associated with the first orbit of\[H{{e}^{+}}\].
What is the radius of the orbit?
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What will be the wavelength of a ball of mass 0.1 kg moving with velocity of \[10m\,{{s}^{-1}}\] ?
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The mass of an electron is \[9.1\times
{{10}^{-31}}kg.\]
If its K.E. is \[3\times {{10}^{-25}}J\], calculate its
wavelength.
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-
Calculate the mass of a photon with wavelength \[3.6\overset{{}^\circ
}{\mathop{A}}\,.\]
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A microscope using suitable photons is employed to locate an
electron in an atom within a distance of \[0.1\,\overset{\text{o}}{\mathop{\text{A}}}\,\].
What is the uncertainty involved in the measurement of its velocity?
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A golf ball has a mass of 40 g and a speed of \[45m\,{{s}^{-1}}\]
. If the speed can be measured within accuracy of 2%, calculate the uncertainty
in the position.
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-
What is the total number of orbitals associated with the
principal quantum number \[n=3\]?
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Using s, p, d, f notations, describe the
orbital with the following quantum numbers.
(a) \[n=2,l=1\] (b)
\[n=4,l=0\]
(c) \[n=5,l=3\] (d) \[n=3,l=2\]
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Calculate number of electrons which will weigh together one
gram.
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Calculate the total number of electrons present in mole of
methane.
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How many neutrons and protons are there in the
following nuclei?
\[_{6}^{13}C,\,_{8}^{16}O,\,_{12}^{24}Mg,\,_{26}^{56}Fe,\,_{38}^{88}Sr\]
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Write down the complete symbol for the atom with
the given atomic number (Z) and atomic mass (A).
(i) Z = 17, A = 35, (ii) Z = 92, A = 233, (iii) Z = 4, A = 9
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Yellow light emitted from a sodium lamp has a wavelength X
of 580 nm. Calculate the frequency (v) and wave number \[(\overset{\_\_}{\mathop{v}}\,)\]
of the yellow light.
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Find the energy of each of the photons which (i) corresponds
to the light of frequency \[3\times {{10}^{15}}\] Hz, (ii) has wavelength of
0.50\[\overset{{}^\circ }{\mathop{\text{A}}}\,\].
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-
Calculate the wavelength, frequency and wave number of a light
whose period is \[2\times {{10}^{-10}}\sec .\]
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What is the number of photons of light with a wavelength of 4000
pm that provide 1 J of energy?
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A photon of wavelength \[4\times {{10}^{-7}}m\] strikes a
metal surface the work function of the metal being 2.13 eV. Calculate (i) the
energy of the photon in eV, (ii) the kinetic energy of the emitted
photoelectron and (iii) the velocity of the photoelectron.
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Electromagnetic radiation of wavelength 242 nm is just sufficient
to ionise a sodium atom. Calculate the ionisation energy of sodium in kJ/mol.
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A 25 watt bulb emits monochromatic yellow light of
wavelength 0.57\[\mu m\] Calculate the rate of emission of quanta per second.
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Electrons are emitted with zero velocity from a metal surface
when it is exposed to the radiation of wavelength 6800\[\overset{{}^\circ
}{\mathop{\text{A}}}\,\]. Calculate threshold frequency (\[{{V}_{0}}\]) and
work junction (\[{{W}_{0}}\]) of the metal.
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What is the wavelength of light emitted when the electron in
hydrogen atom undergoes transition from an energy level with \[n=4\] to \[n=2\]?
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How much energy is required to ionise a H-atom if the electron
occupies \[n=5\] orbit? Compare your answer with the ionisation enthalpy of
H-atom (energy required to remove the electron from \[n=1\]orbit).
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What is the maximum number of emission lines when the excited
electron of H-atoms in \[n=6\] drops to the ground state?
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(i) The energy associated with the first orbit of
hydrogen atom is \[-2.18\times {{10}^{-18}}J\]. What is the energy associated with
the fifth orbit?
(ii) Calculate the radius of Bohr's fifth orbit of hydrogen atom.
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-
Calculate the wave number for the longest wavelength transition
in the Balmer series of atomic hydrogen.
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What is the energy in joules, required to shift the electron
of a hydrogen atom from first Bohr orbit to fifth Bohr orbit and what is the
wavelength of the light emitted when the electron returns to the ground state?
The ground state electron energy is \[-2.18\times {{10}^{-11}}erg.\] erg.
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The electron energy in hydrogen atom is given by \[{{E}_{n}}=-\frac{2.18\times
{{10}^{-18}}}{{{n}^{2}}}J.\]. Calculate the energy required to remove an
electron completely from the \[n=2\] orbit. What is the longest wavelength of
light in cm that can be used to cause this transition?
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Calculate the wavelength of an electron moving with a
velocity \[2.05\times {{10}^{7}}m{{s}^{-1}}.\]
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The mass of an electron is \[9.1\times {{10}^{-31}}kg.\]. If
its K.E. is \[3\times {{10}^{-25}}J\], calculate its wavelength.
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Which of the following are isoelectronic species,
i.e., those having the same number of electrons?
\[\mathbf{N}{{\mathbf{a}}^{\mathbf{+}}}\mathbf{,M}{{\mathbf{g}}^{\mathbf{2+}}}\mathbf{,}{{\mathbf{K}}^{\mathbf{+}}}\mathbf{,C}{{\mathbf{a}}^{\mathbf{2+}}}\mathbf{,}{{\mathbf{S}}^{\mathbf{2-}}}\mathbf{,Ar}\]
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(i) Write down the electronic configurations of the
following ions:
(a) \[{{H}^{-}}\] (b) \[N{{a}^{+}}\] (c) \[{{O}^{2-}}\]
(d) \[{{F}^{-}}\]
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What is the lowest value of 'n that allows g orbitals to exist?
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An electron is in one of the 3d-orbitals, Give the possible values
of n, I and \[{{m}_{l}}\] for this electron.
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-
An atom of an element contains 29 electrons and 35 neutrons.
Deduce: (i) the number of protons and (ii) the electronic configuration of the
element.
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-
Give the numer of electrons in the species \[H_{2}^{+},{{H}_{2}}\]and
\[O_{2}^{+}\].
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An element has \[n=3\]. What are the possible values of \[l\]
and\[{{m}_{l}}\]?
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Using s, p, d notations, describe the
orbital with the following quantum numbers.
(a) \[n=1,\,l=0\] (b)
\[n=3,\,l=1\]
(c) \[n=4,\,l=2\] (d)
\[w=4,\,l=3\]
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Explain, giving reasons which of the following
sets of quantum numbers are not possible?
(a) \[n=1,l=0,{{m}_{l}}=0,{{m}_{s}}=+\frac{1}{2}\]
(b) \[n=1,l=0,{{m}_{l}}=0,{{m}_{s}}=-\frac{1}{2}\]
(c) \[n=1,l=1,{{m}_{l}}=0,{{m}_{s}}=+\frac{1}{2}\]
(d) \[n=2,l=1,{{m}_{l}}=0,{{m}_{s}}=-\frac{1}{2}\]
(e) \[n=3,l=3,{{m}_{l}}=-3,{{m}_{s}}=+\frac{1}{2}\]
(f) \[n=3,l=1,{{m}_{l}}=0,{{m}_{s}}=+\frac{1}{2}\]
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How many electrons in an atom may have
the following quantum numbers?
(a) \[n=4,{{m}_{s}}=-\frac{1}{2}\]
(b) \[n=3,l=0\]
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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.
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-
What transition in the hydrogen atom spectrum would
have the same wavelength as the Balmer transition \[n=4\]
to \[n=2\] of \[H{{e}^{+}}\] spectrum?
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Calculate the energy required for the process,
\[H{{e}^{+}}(g)\to H{{e}^{2+}}(g)+{{e}^{-}}\]
The ionization energy for H-atom in the ground state is \[2.18\times
{{10}^{-18}}J\,ato{{m}^{-1}}.\]
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If the diameter of a carbon atom is 0.15 nm, calculate the number
of carbon atoms which can be placed side by side in straight line across the
length of scale of 20 cm long.
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\[2\times {{10}^{8}}\]atoms of carbon are arranged
side by side.
Calculate the radius of carbon atom if the length of this arrangement
is 3 cm.
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The diameter of zinc atom is 2.6 A. Calculate : (a) radius of zinc atom in pm and (b) number of atoms present in a length of 1.6 cm if the zinc atoms are arranged side by side length wise.
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-
A certain particle carries \[2.5\times {{10}^{-16}}C\] of
static electric charge. Calculate the number of electrons present in it.
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In Millikan's experiment, static electric charge on the oil drops
has been obtained by shining X-rays. If the static electric charge on the oil
drop is \[-1.282\times {{10}^{-18}}C,\]calculate the number of electrons
present in it.
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In Rutherford's experiment, generally the thin foil of heavy
atoms like gold, platinum etc., have been used to be bombarded by the \[\alpha
\]-particles. If the thin foil of light atoms like aluminium etc., is used,
what difference would be observed from the above results?
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Symbols \[_{35}^{79}Br\] and \[{{\,}^{79}}Br\] can be
written, whereas symbols\[\,_{79}^{35}Br\] and \[{{\,}^{35}}Br\] are not
acceptable. Answer briefly.
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An element with mass number 81 contains 31.7% more neutrons
as compared to protons. Assign the atomic symbol.
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-
An ion with mass number 37 possesses one unit of negative charge.
If the ion contains 11.1% more neutrons than electrons, find the symbol of the
ion.
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An ion with mass number 56 contains 3 units of positive charge
and 30.4% more neutrons than electrons. Assign the symbol of this ion.
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-
Arrange the following types of
radiations in increasing order of frequency:
(a) radiation from microwave
oven
(b) amber light from traffic
signal
(c) radiation from FM radio
(d) cosmic rays from outer space
(e) X-rays
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Nitrogen laser produces a radiation at a wavelength of 337.1
nm. If the number of photons emitted is\[5.6\times {{10}^{24}}\], calculate power
of this laser.
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Neon gas is generally used in the signboards. If it is
emitted strongly at 616 nm. Calculate: (a) the frequency of emission (b)
distance travelled by the radiation in 30 sec (c) energy of quantum and (d)
number of quanta present if it produces 2 J energy.
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In astronomical observations, signals observed from the distant
stars are generally weak. If the photon detector receives a total of \[3.15\times
{{10}^{-18}}\] from the radiation of 600 nm, calculate the number of photons
received by the detector.
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Lifetimes of the molecules in the excited state are often measured
by using a pulse radiation source of duration nearly in nano second range. If
the radiation source has the duration of 2 ns and the number of photons emitted
during the pulse source is \[2.5\times {{10}^{15}}\], calculate the energy of
the source.
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The longest wavelength doublet absorption transition is observed
at 589 and 589.6 nm. Calculate the frequency of each transition and the energy
difference between two excited states.
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Work function of caesium metal is 1.9 eV. Calculate: (a) the
threshold wavelength (b) the threshold frequency of the radiation (c) If the
caesium metal is irradiated with a wavelength of 500 nm, calculate the kinetic
energy and velocity of the ejected electron.
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Following results were observed when
sodium metal is irradiated with different wavelengths. Calculate:
(a) Threshold wavelength
(b) Planck's constant
\[\begin{align}
& \lambda
nm\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,500\,\,\,\,\,\,\,\,450\,\,\,\,\,\,\,\,\,\,\,400
\\
& \upsilon \times
{{10}^{6}}m{{s}^{-1}}\,\,\,\,\,2.55\,\,\,\,\,\,4.35\,\,\,\,\,\,\,\,\,5.20 \\
\end{align}\]
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The ejection of photoelectron from the silver metal
in the photoelectric effect experiment can be stopped by applying the voltage
of 035 when the radiation 256.7 nm is used.
Calculate the work function for silver metal.
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If photon of wavelength 150 pm strikes on an atom and one of
its inner bound electrons is ejected out with velocity of\[1.5\times
{{10}^{7}}m\,{{\sec }^{-1}}\]. Calculate energy with which it is bound to the
nucleus.
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Emission transitions in the Paschen series end at
an orbit of \[n=3\] and start from orbit n and can be represented as,
\[v=3.29\times {{10}^{15}}Hz\left[
\frac{1}{{{3}^{2}}}-\frac{1}{{{n}^{2}}} \right]\]
Calculate the value of 'n' if the transition is observed at 1285
nm. Find the region of the spectrum.
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Calculate the wavelength for the emission transition if it starts
from the orbit having radius 1.3225 nm and ends at 211.6 pm. Name the series to
which this transition belongs and the region of the spectrum.
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Dual behaviour of matter proposed by de Broglie led to the discovery
of electron microscope often used for the highly magnified images of biological
molecules and other types of material. If the velocity of electron in this
microscope is \[1.6\times {{10}^{6}}m\,{{s}^{-1}}\], calculate the de Broglie
wavelength associated with this electron.
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Similar to electron diffraction, neutron diffraction microscope
is also used for the determination of the structure of molecules. If the
wavelength used here is 800 pm, calculate characteristic velocity associated
with neutron.
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If the velocity of electron in Bohr's first orbit is\[2.19\times
{{10}^{6}}m\,{{\sec }^{-1}}\], calculate the de Broglie wavelength associated
with it.
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The velocity associated with proton moving in a potential difference
of \[1000\,V\] is\[4.37\times {{10}^{5}}m\,{{s}^{-1}}\]. If a hockey ball of
mass 0.1 kg is moving with this velocity, calculate the wavelength associated
with this velocity.
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If the position of an electron is measured within an accuracy
of \[\pm 0.002\,nm,\] calculate the uncertainty in momentum of the electron.
Suppose the momentum of electron is \[\frac{h}{4\pi \times 0.05}\], is there
any problem in defining this value?
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Quantum numbers of six electrons are
given below.
Arrange them in the order of
increasing energies. If any of these combinations) has/have the same energy
list them
1. \[n=4,l=2,{{m}_{l}}=-2,{{m}_{s}}=-1/2\]
2. \[n=3,l=2,{{m}_{l}}=1,{{m}_{s}}=+1/2\]
3. \[n=4,l=1,{{m}_{l}}=0,{{m}_{s}}=+1/2\]
4. \[n=3,l=2,{{m}_{l}}=-2,{{m}_{s}}=-1/2\]
5. \[n=3,l=1,{{m}_{l}}=-1,{{m}_{s}}=+1/2\]
6. \[n=4,l=1,{{m}_{l}}=0,{{m}_{s}}=+1/2\]
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The bromine atom possesses 35 electrons. It
contains 6 electrons in 2p-orbitals; 6 electrons in 3p-orbitals and 5 electrons
in 4p-orbitals. Which of these electrons experiences the lowest effective
nuclear charge?
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Among the following pairs of orbitals,
which orbital will experience the larger effective nuclear charge?
(a) 2s and 3s (b) 4d and 4f (c)
3d and 3p
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The unpaired electrons in Al and Si are present in 3p- orbitals.
Which electron will experience more effective nuclear charge from nucleus?
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Indicate the number of unpaired electrons
in:
(a) P (b) Si (c) Cr (d) Fe and (e) Kr
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(a) How many sub-shells are associated with \[n=4\]?
(b) How many electrons will be present in the subshells having
\[{{m}_{s}}\] value of for \[n=4\]?
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question_answer87)
Which of the following conclusions could
not be derived from Rutherford's \[\alpha \]-particle scattering experiment?
(a) Most of the space in the
atom is empty
(b) The radius of the atom is
about \[{{10}^{-10}}\] while that of nucleus is \[{{10}^{-15}}m\]
(c) Electrons move in a circular
path of fixed energy called orbits
(d) Electrons and the nucleus
are held together by electrostatic forces of attraction
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question_answer88)
Which of the following options does not
represent ground state electronic configuration of an atom?
(a)
\[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{8}}4{{s}^{2}}\]
(b) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{9}}4{{s}^{2}}\]
(c) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{1}}\]
(d) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{5}}4{{s}^{1}}\]
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question_answer89)
The probability density plots of 1s and
2s orbitals are given in figure:
The density of dots in a region
represents the probability density of finding electrons in the region.
On the basis of above diagram
which of the following statements is incorrect?
(a) 1s and 2s orbitals are
spherical in shape
(b) The probability of finding
the electron is maximum near the nucleus
(c) The probability of finding
the electron at a given distance is equal in all directions
(d) The probability density of
electrons for 2s orbital decreases uniformly as distance from the nucleus Increases
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question_answer90)
Which of the following
statements is not correct about the characteristics of cathode rays?
(a) They start from the cathode
and move towards the anode
(b) They travel in straight line
in the absence of an external electrical or magnetic field
(c) Characteristics of cathode
rays do not depend upon the material of electrodes in cathode ray tube
(d) Characteristics of cathode
rays depend upon the nature of gas present in the cathode ray tube
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question_answer91)
Which of the following
statements about the electron is incorrect?
(a) It is a negatively charged
particle
(b) The mass of electron is
equal to the mass of neutron
(c) It is a basic constituent of
all atoms
(d) It is a constituent of
cathode rays
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question_answer92)
Which of the following
properties of atom could be explained correctly by Thomson Model of atom?
(a) Overall neutrality of atom
(b) Spectra of hydrogen atom
(c) Position of electrons,
protons and neutrons in atom
(d) Stability of atom
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question_answer93)
Two atoms are said to be isobars
if:
(a) they have same atomic number
but different mass number
(b) they have same number of
electrons but different number of neutrons
(c) they have same number of
neutrons but different number of electrons
(d) sum of the number of protons
and neutrons is same but the number of protons is different
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question_answer94)
The number of radial nodes for
3p orbitals is:
(a) 3 (b)
4
(c) 2 (d)
1
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question_answer95)
Number of angular nodes for 4d
orbitals is:
(a) 4 (b)
3
(c) 2 (d)
1
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question_answer96)
Which of the following is
responsible to rule out the existence of definite paths or trajectories of
electrons?
(a) Pauli's exclusion principle
(b) Heisenberg's uncertainty
principle
(c) Hund's rule of maximum
multiplicity
(d) Aufbau principle
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question_answer97)
Total number of orbitals
associated with third shell will be:
(a) 2 (b)
4
(c) 9 (d)
3
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question_answer98)
Orbital angular momentum depends
on:
(a) \[l\] (b)
n and \[l\]
(c) n and m (d)
m and s
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question_answer99)
Chlorine exists in two isotopic
forms, \[Cl-37\] and \[Cl-35\] but its atomic mass is 35.5. This indicates the
ratio of \[Cl-37\] and \[Cl-35\] is approximately:
(a) 1 : 2 (b)
1 : 1
(c) 1 : 3 (d)
3 : 1
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question_answer100)
The pair of ions having same
electronic configuration is:
(a) \[C{{r}^{3+}},F{{e}^{3+}}\]
(b) \[F{{e}^{3+}},M{{n}^{2+}}\]
(c) \[F{{e}^{3+}},C{{o}^{3+}}\]
(d) \[S{{c}^{3+}},C{{r}^{3+}}\]
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question_answer101)
For the electrons of oxygen
atom, which of the following statements is correct?
(a) \[{{Z}_{eff}}\] for an
electron in a 2s orbital is the same as \[{{Z}_{eff}}\] for an electron in a 2p
orbital
(b) An electron in the 2s
orbital has the same energy as an electron in the 2p orbital
(c) \[{{Z}_{eff}}\] for an
electron in Is orbital is the same as \[{{Z}_{eff}}\]for an electron in a 2s
orbital
(d) The two electrons present in
the 2s orbital have spin quantum numbers \[{{m}_{s}}\] but of opposite sign.
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question_answer102)
If travelling at same speeds,
which of the following matter waves have the shortest wavelength?
(a) Electron
(b) Alpha particle (\[H{{e}^{2+}}\])
(c) Neutron
(d) Proton
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question_answer103)
Identify the pairs which are not of
isotopes?
(a) \[\,_{6}^{12}X,\,_{6}^{13}Y\] (b)
\[\,_{17}^{35}X,\,_{17}^{37}Y\]
(c) \[\,_{6}^{14}X,\,_{7}^{14}Y\] (d)
\[\,_{4}^{8}X,\,_{5}^{8}Y\]
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question_answer104)
Out of the following pairs of
electrons, identify the pairs of electrons present in degenerate orbitals:
(a) (i) \[n=3,l=2,{{m}_{l}}=-2,{{m}_{s}}=-\frac{1}{2}\]
(ii) \[n=3,l=2,{{m}_{l}}=-1,{{m}_{s}}=-\frac{1}{2}\]
(b) (i) \[n=3,l=1,{{m}_{l}}=1,{{m}_{s}}=+\frac{1}{2}\]
(ii) \[n=3,\,\,l=2,\,\,{{m}_{l}}=1,\,\,{{m}_{s}}=+\frac{1}{2}\]
(c) \[n=4,l=1,{{m}_{l}}=1,{{m}_{s}}=+\frac{1}{2}\]
(ii) \[n=3,l=2,{{m}_{l}}=1,{{m}_{s}}=+\frac{1}{2}\]
(d) (i) \[n=3,l=2,{{m}_{l}}=+2,{{m}_{s}}=-\frac{1}{2}\]
(ii) \[n=3,l=2,{{m}_{l}}=+2,{{m}_{s}}=+\frac{1}{2}\]
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question_answer105)
Which of the following sets of
quantum numbers are correct?
\[n\] \[l\] \[{{m}_{1}}\]
(a) 1 1 +
2
(b) 2 1 +
1
(c) 3 2 ?
2
(d) 3 4 ?
2
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question_answer106)
In which of the following pairs,
the ions are isoelectronic?
(a) \[N{{a}^{+}},M{{g}^{2+}}\] (b)
\[A{{l}^{3+}},{{O}^{-}}\]
(c) \[N{{a}^{+}},{{O}^{2-}}\] (d)
\[{{N}^{3-}},C{{l}^{-}}\]
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question_answer107)
Which of the following
statements concerning the quantum numbers are correct?
(a) Angular quantum number
determines the three dimensional shape of the orbital
(b) The principal quantum number
determines the orientation and energy of the orbital
(c) Magnetic quantum number
determines the size of the orbital
(d) Spin quantum number of an
electron determines the orientation of the spin of electron relative to the
chosen axis
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question_answer108)
Arrange s, p, d subshells of a shell in
the increasing order of effective nuclear charge \[({{Z}_{eff}})\] experienced
by the electron present in them.
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question_answer109)
Show the distribution of
electrons in oxygen atom (atomic number 8) using orbital diagram.
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question_answer110)
Nickel atom can lose two
electrons to form \[N{{i}^{2+}}\] ion. The atomic number of nickel is 28. From
which orbital will nickel lose two electrons?
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question_answer111)
Which of the following orbitals
are degenerate?
\[3{{d}_{xy}},4{{d}_{xy}}3{{d}_{yz}},4{{d}_{yz}},4{{d}_{{{z}^{2}}}}\]
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question_answer112)
Calculate the total number of
angular nodes and radial nodes present in 3p orbital.
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question_answer113)
The arrangement of orbitals on
the basis of energy is based upon their \[(n+l)\] value. Lower the value of\[(n+l)\],
lower is the energy. For orbitals having same values of\[(n+l)\], the orbital
with lower value of n will have lower energy.
(i) Based upon the above
information, arrange the following orbitals in the increasing order of energy.
(a) 1s, 2s, 3s, 2p (b)
4s, 3s, 3p, 4d
(c) 5p, 4d, 5d, 4f, 6s (d)
5f, 6d, 7s, 1p
(ii) Based upon the above
information, solve the questions given below:
(a) Which of the following
orbitals has the lowest energy?
\[4d,5f,5s,5p\]
(b) Which of the following
orbitals has the highest energy?
\[5p,5d,5f,6s,6p\]
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question_answer114)
Which of the following will not show
deflection from the path on passing through an electric field?
Proton, cathode rays, electron,
neutron
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question_answer115)
An atom having atomic mass
number 13 has 7 neutrons. What is the atomic number of the atom?
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question_answer116)
Wavelengths of different
radiations are given below:
\[\lambda (A)=300nm,\lambda
(B)=300\mu m,\lambda (C)=3nm,\]
\[\lambda
(D)=30\overset{\text{o}}{\mathop{\text{A}}}\,\]
Arrange these radiations in the
increasing order of the energies.
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question_answer117)
The electronic configuration of
valence shell of
\[Cu\] is \[3{{d}^{10}},4{{s}^{1}}\]
and not \[3{{d}^{9}},4{{s}^{2}}\]. How is this configuration explained?
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question_answer118)
The Balmer series in the
hydrogen spectrum correspond to the transition from \[{{n}_{1}}=2\]to \[{{n}_{2}}=3,4.....\]This
series lie in the visible region. Calculate the wave number of line associated
with the transition in Balmer series when the electron moves to \[n=4\] orbit.\[({{R}_{H}}=109677c{{m}^{-1}})\]
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question_answer119)
According to de Broglie, matter
should exhibit dual behaviour, that is both particle and wave like properties However,
a cricket ball of mass 100 g does not move like wave when it is thrown by a
bowler at a speed of 100 km/h. Calculate the wavelength of the ball and explain
why it does not show wave nature.
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question_answer120)
What is the experimental
evidence in support of the idea that electronic energy in an atom are quantised?
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question_answer121)
Out of electron and proton,
which one will have, a highs velocity to produce matter waves of the same
wavelength Explain it.
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question_answer122)
A hypothetical electromagnetic
wave is shown in figure Find out the wavelength of the radiation.
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question_answer123)
Chlorophyll present in green
leaves of plants absorbs light at \[4.62\times {{10}^{14}}Hz.\]Calculate the
wavelength of radiation) nanometer. Which part of the electromagnetic spectrum does
it belong to?
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question_answer124)
What is the difference between
the terms orbit and orbital
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question_answer125)
Table-tennis ball has a mass 10
g and a speed of \[90\,\,m\,\,{{\sec }^{-1}}\].
If speed can be measured within
an accuracy of 4% what will be the uncertainty in speed and position?
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question_answer126)
The effect of uncertainty
principle is significant only for motion of microscopic particles and is
negligible for the macroscopic particles. Justify the statement with the help
of a suitable example.
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question_answer127)
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?
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question_answer128)
In some of the following questions,
one option of left column may be correlated to more than one option in the right
column.
Match the following species with
their corresponding ground state electronic configuration:
|
Atom/Ion
|
Electronic configuration
|
(i)
|
\[Cu\]
|
(a) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}\]
|
(ii)
|
\[C{{u}^{2+}}\]
|
(b) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{2}}\]
|
(iii)
|
\[Z{{n}^{2+}}\]
|
(c) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}4{{s}^{1}}\]
|
(iv)
|
\[C{{r}^{3+}}\]
|
(d) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{9}}\]
|
|
|
(e) \[1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{3}}\]
|
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question_answer129)
Match the quantum numbers with
the information provided by these.
Quantum number
|
Information provided
|
(i) Principal quantum number
|
(a) orientation of the orbital
|
(ii) Azimuthal quantum number
|
(b) energy and size of orbital
|
(iii) Magnetic quantum number
|
(c) spin of electron
|
(iv) Spin quantum number
|
(d) shape of the orbital
|
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question_answer130)
Match the following rules with their
statements:
|
Rules
|
Statements
|
(i)
|
Hund?s Rule
|
(a) No two electrons in an atom can have the same
set of four quantum number.
|
(ii)
|
Aufbau Principle
|
(b) Half-filled and completely filled orbitals
have extra stability.
|
(iii)
|
Pauli?s Exclusion Principle
|
(c) Pairing of electrons in the orbitals
belonging to the same subshell does not take place until each orbital is
singly occupied.
|
(iv)
|
Heisenberg?s Uncertainty Principle
|
(d) It is impossible to determine the exact
position and exact momentum of a subatomic particle simultaneously.
|
|
|
(e) On the ground state of atoms, orbitals are
filled in the order of their increasing energies.
|
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question_answer131)
Match the following:
Column I
|
Column II
|
(i) X-rays
|
(a) \[v={{10}^{0}}-{{10}^{4}}Hz\]
|
(ii) UV-rays
|
(b) \[v={{10}^{10}}Hz\]
|
(iii) Long radio waves
|
(c) \[v={{10}^{16}}Hz\]
|
(iv) Microwave
|
(d) \[v={{10}^{18}}Hz\]
|
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question_answer132)
Match the following:
Column I
|
Column II
|
(i) Photon
|
(a) Value is 4 for N shell
|
(ii) Electron
|
(b) Probability density
|
(iii) \[{{\psi }^{2}}\]
|
(c) Always positive value
|
(iv) Principal quantum number n
|
(d) Exhibits both momentum and wavelength
|
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question_answer133)
Match the species given in column I with
the electronic configuration given in column II.
Column I
|
Column II
|
(i) Cr
|
(a) \[[Ar]3{{d}^{8}}4{{s}^{0}}\]
|
(ii) \[F{{e}^{2+}}\]
|
(b) \[[Ar]3{{d}^{10}}4{{s}^{1}}\]
|
(iii) \[N{{i}^{2+}}\]
|
(c) \[[Ar]3{{d}^{6}}4{{s}^{0}}\]
|
(iv) \[Cu\]
|
(d) \[[Ar]3{{d}^{5}}4{{s}^{1}}\]
|
|
(e) \[[Ar]3{{d}^{6}}4{{s}^{2}}\]
|
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question_answer134)
In
the following questions a statement of Assertion (A) followed by a statement of
Reason (R) is given. Choose the correct option out of the choices given below:
(a) A and R both are true and R is the
correct explanation of A.
(b) A and R both are true but R
is not the correct explanation of A.
(c) A is true but R is false.
(d) A and R both are false.
Assertion (A): All
isotopes of a given element show the same type of chemical behaviour.
Reason (R): The chemical
properties of an atom are controlled by the number of electrons in the atom.
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question_answer135)
Assertion (A): Black body
is an ideal body that emits and absorbs radiations of all frequencies.
Reason (R): The frequency
of radiation emitted by a body goes from a lower frequency to higher frequency
with an increase in temperature.
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question_answer136)
Assertion (A): It is
impossible to determine the exact position and exact momentum of an electron simultaneously.
Reason (R): The path of
an electron in an atom is clearly defined.
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question_answer137)
What is photoelectric effect?
State the result of photoelectric effect experiment that could not be explained
on the basis of laws of classical physics. Explain this effect on the basis of quantum
theory of electromagnetic radiations.
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question_answer138)
Threshold frequency, \[{{v}_{0}}\]
is the minimum frequency which a photon must possess to eject an electron form
a metal. It is different for different metals. When a photon of frequency \[1.0\times
{{10}^{15}}{{s}^{-1}}\] was allowed to hit a metal surface, an electron having \[1.988\times
{{10}^{-19}}J\] of kinetic energy was emitted.
Calculate the threshold frequency of
this metal. Show that an electron will not be emitted if a photon with a wavelength
equal to 600 nm hits the metal surface.
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question_answer139)
When an electric discharge is passed
through hydrogen gas, the hydrogen molecules dissociate to produce excited hydrogen
atoms. These excited atoms emit electromagnetic radiation of discrete
frequencies which can be given by the general formula
\[\overline{v}=109677\left[ \frac{1}{n_{i}^{2}}-\frac{1}{n_{f}^{2}}
\right]\]
What points of Bohr's model of an atom
can be used to arrive at this formula? Based on these points derive the above
formula giving description of each step and each term.
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question_answer140)
Calculate the energy and
frequency of the radiation emitted when an electron jumps from \[n=3\] to \[n=2\]
in a hydrogen atom.
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question_answer141)
Why was a change in the Bohr's
Model of atom required? Due to which important development(s), concept of movement
of an electron in an orbit was replaced by the concept of probability of
finding electron in an orbital?
What is the name given to the
changed model of atom?
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