A Complete Resource Book in Chemistry for JEE Main

A.K. Singhal

Chapter 4

Atomic Structure - all with Video Answers

Educators

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Chapter Questions

Problem 1

How many $\mathrm{e}^{-}$are present in p-sub-orbits in $\mathrm{Zn}$-atom?
(a) 2
(b) 6
(c) 12
(d) 18

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 2

Wavelength of spectral line emitted is inversely proportional to
(a) energy
(b) velocity
(c) radius
(d) quantum number

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 3

The number of electrons, neutrons and protons in a species are equal to 10,8 and 8 respectively. The proper symbol of the species is
(a) ${ }^{16} \mathrm{O}_{8}$
(b) ${ }^{18} \mathrm{O}_{8}$
(c) ${ }^{18} \mathrm{Ne}_{10}$
(d) ${ }^{16} \mathrm{O}_{8}^{-2}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 4

Which set has same number of unpaired electrons?
(a) $\mathrm{Fe}^{2+}, \mathrm{Mn}^{+2}$
(b) $\mathrm{Fe}^{3+}, \mathrm{Mn}^{+2}$
(c) $\mathrm{Cr}^{+3}, \mathrm{Ni}^{2+}$
(d) $\mathrm{Zn}^{2+} \mathrm{Cu}^{2+}$

Preeti Kumari

Numerade Educator

Problem 5

Which one of the following forms a colourless solution in aqueous medium?
(a) $\mathrm{V}^{3+}$
(b) $\mathrm{Cr}^{3+}$
(c) $\mathrm{Ti}^{3+}$
(d) $\mathrm{Sc}^{3}$
Atomic number $\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 6

The incorrect configuration is
(a) $\mathrm{K}=[\mathrm{Ar}] 4 \mathrm{~s}^{\mathrm{l}}$
(b) $\mathrm{Cr}=[\mathrm{Ar}] 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{1}$
(c) $\mathrm{Cr}=[\mathrm{Ar}] 3 \mathrm{~d}^{4} 4 \mathrm{~s}^{2}$
(d) $\mathrm{Cu}=[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^{1}$

Preeti Kumari

Numerade Educator

Problem 7

Which of the following elements has least number of electrons in its M shell?
(a) $\mathrm{Mn}$
(b) $\mathrm{Ni}$
(c) $\mathrm{K}$
(d) $\mathrm{Sc}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 8

In which orbital is the angular momentum of an electron zero?
(a) $2 \mathrm{p}$
(b) $2 \mathrm{~s}$
(c) $3 \mathrm{~d}$
(d) $4 \mathrm{f}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 9

Chromium is represented by the electronic configuration
(a) $[\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6} 3 \mathrm{~d}^{1} 4 \mathrm{~s}^{2}$
(b) $[\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6} 3 \mathrm{~d}^{2} 4 \mathrm{~s}^{1}$
(c) $[\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6} 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{1}$
(d) $[\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6} 4 \mathrm{~s}^{2} 3 \mathrm{~d}^{4}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 10

The correct set of quantum numbers is
(a) $\mathrm{n}=2, l=1, \mathrm{~m}=-2, \mathrm{~s}=0$
(b) $\mathrm{n}=2, l=-2, \mathrm{~m}=1, \mathrm{~s}=+1 / 2$
(c) $\mathrm{n}=2, l=2, \mathrm{~m}=-1, \mathrm{~s}=-1 / 2$
(d) $\mathrm{n}=2, l=1, \mathrm{~m}=0, \mathrm{~s}=+1 / 2$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 11

The values of four quantum numbers of valence electron of an element are $\mathrm{n}=4, l=0, \mathrm{~m}=0$ and $\mathrm{s}=+1 / 2$. The element is
(a) $\mathrm{Ti}$
(b) $\mathrm{K}$
(c) $\mathrm{Na}$
(d) $\mathrm{Sc}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 12

Set of isoelectronic species is
(a) $\mathrm{H}_{2}, \mathrm{CO}_{2}, \mathrm{CN}^{-}, \mathrm{O}^{-}$
(b) $\mathrm{N}, \mathrm{H}_{2} \mathrm{~S}, \mathrm{CO}$
(c) $\mathrm{N}_{2}, \mathrm{CO}, \mathrm{CN}^{-}, \mathrm{O}_{2}^{+2}$
(d) $\mathrm{Ca}, \mathrm{Mg}, \mathrm{Cl}$

Preeti Kumari

Numerade Educator

Problem 13

Number of orbitals in $L$ energy level
(a) 1
(b) 2
(c) 3
(d) 4

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 14

Ratio of radii of second and first Bohr orbits of $\mathrm{H}$ atom
is
(a) 2
(b) 4
(c) 3
(d) 4

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 15

If a source of power $4 \mathrm{Kw}$ produces $10^{20}$ photon Per second, the radiation belongs to a part of the spectrum called
(a) $\gamma$-Rays
(b) U.V Rays
(c) Microwaves
(d) X-Rays

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 16

The outer most configuration of most electronegative element is
(a) $\mathrm{ns}^{2} \mathrm{np}^{5}$
(b) $\mathrm{ns}^{2} \mathrm{np}^{6}$
(c) $\mathrm{ns}^{2} \mathrm{np}^{4}$
(d) $\mathrm{ns}^{2} \mathrm{np}^{6}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 17

Which one of the following expressions represent the electron probability function D?
(a) $4 \pi \mathrm{rr} \mathrm{dr} \psi^{2}$
(b) $4 \pi \mathrm{r}^{2} \mathrm{dr} \psi$
(c) $4 \pi \mathrm{rr}^{2} \mathrm{dr} \psi^{2}$
(d) $4 \pi \mathrm{dr} \psi$

Preeti Kumari

Numerade Educator

Problem 18

If the electron of a hydrogen atom is present in the first orbit, the total energy of the electron is
(a) $-\mathrm{e}^{2} / 2 \mathrm{r}$
(b) $-\mathrm{e}^{2} / \mathrm{r}$
(c) $-\mathrm{e}^{2} / \mathrm{r}^{2}$
(d) $-\mathrm{e}^{2} / 2 \mathrm{r}^{2}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 19

Quantum numbers of an atom can be defined on the basis of
(a) Aufbau's principle
(b) Heisenberg's uncertainity principle
(c) Hund's rule
(d) Pauli's exclusion principle

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 20

Which of the following is isoelectronic?
(a) $\mathrm{CO}_{2}, \mathrm{NO}_{2}$
(b) $\mathrm{NO}_{2}^{-}, \mathrm{CO}_{2}$
(c) $\mathrm{CN}^{-}, \mathrm{CO}$
(d) $\mathrm{SO}_{2}, \mathrm{CO}_{2}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 21

Which of the following do not travel with speed of light?
(a) De-Broglie waves
(b) X-rays
(c) Gamma rays
(d) All of these

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 22

How many electrons can be accommodated in a p-orbital?
(a) 6 electrons
(b) 2 electrons
(c) 4 electrons
(d) none of these

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 23

The quantum number 'm' of a free gaseous atom is associated with
(a) the effective volume of the orbital
(b) the shape of the orbital
(c) the spatial orientation of the orbital
(d) the energy of the orbital in the absence of a magnetic field

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 24

In ground state, an element has 13 electrons in its $\mathrm{M}$ shell. The element is
(a) copper
(b) iron
(c) nickel
(d) chromium

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 25

Which of the following pair of ions have same para magnetic moment?
(a) $\mathrm{Cu}^{2+}, \mathrm{Ti}^{3+}$
(b) $\mathrm{Ti}^{3+}, \mathrm{Ni}^{2+}$
(c) $\mathrm{Ti}^{4+}, \mathrm{Cu}^{2+}$
(d) $\mathrm{Mn}^{2+}, \mathrm{Cu}^{2+}$

Preeti Kumari

Numerade Educator

Problem 26

The following quantum numbers are possible for how many orbital? $\mathrm{n}=3, l=2, \mathrm{~m}=+2$
(a) 1
(b) 2
(c) 3
(d) 4

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 27

The number of nodal planes in a px orbital is
(a) 1
(b) 2
(c) 3
(d) 0

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 28

How many d-electrons are present in $\mathrm{Cr}^{2+}$ ion?
(a) 5
(b) 6
(c) 3
(d) 4

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 29

$l=3$, then the values of magnetic quantum numbers are $\AA$
(a) $\pm 1, \pm 2, \pm 3$
(b) $0, \pm 1, \pm 2, \pm 3$
(c) $-1,-2,-3$
(d) $0,+1,+2,+3$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 30

Which one of the following pairs of ions have the same electronic configuration?
(a) $\mathrm{Sr}^{3+}, \mathrm{Cr}^{3+}$
(b) $\mathrm{Fe}^{3+}, \mathrm{Mn}^{2+}$
(c) $\mathrm{Fe}^{3+}, \mathrm{Co}^{3+}$
(d) $\mathrm{Cr}^{3+}, \mathrm{Fe}^{3+}$

Preeti Kumari

Numerade Educator

Problem 31

The radius of hydrogen atom is $0.53 \AA$. The radius of $\mathrm{Li}^{2+}$ is of
(a) $1.27 \AA$
(b) $0.17 \AA$
(c) $0.57 \AA$
(d) $0.99 \AA$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 32

The atomic number of an element is 35 . What is the total number of electrons present in all the p-orbitals of the ground state atom of that element?
(a) 17
(b) 11
(c) 23
(d) 6

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 33

The atomic number of an element is 17 . The number of orbitals electron pairs in its valence shell is
(a) 3
(b) 4
(c) 6
(d) 8

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 34

The correct representation for $\mathrm{d}$ orbital is
(a) $(\mathrm{n}-1) \mathrm{d}^{1-9} \mathrm{~ns}^{1}$
(b) $(\mathrm{n}-1) \mathrm{d}^{1-10} \mathrm{~ns}^{1-2}$
(c) $(\mathrm{n}-1) \mathrm{d}^{1-5}$
(d) $(\mathrm{n}-\mathrm{l}) \mathrm{d}^{1-\mathrm{wo}} \mathrm{ns}^{2}$

Hast Aggarwal

Numerade Educator

Problem 35

An element has 2 electrons in its $\mathrm{K}$ shell, 8 electrons in $\mathrm{L}$ shell, 13 electrons in $\mathrm{M}$ shell and one electron in N shell. The element is
(a) $\mathrm{Cr}$
(b) $\mathrm{Fe}$
(c) V
(d) $\mathrm{Ti}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 36

Effective magnetic moment of $\mathrm{Sc}^{3+}$ ion is
(a) 0
(b) $1.73$
(c) $2.83$
(d) $3.87$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 37

Which of the following is not possible?
(a) $\mathrm{n}=2, l=1, \mathrm{~m}=0$
(b) $\mathrm{n}=2, l=0, \mathrm{~m}=-1$
(c) $\mathrm{n}=3, l=0, \mathrm{~m}=0$
(d) $\mathrm{n}=3, l=1, \mathrm{~m}=-1$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 38

The most probable radius (in $\mathrm{pm}$ ) for finding the electron in $\mathrm{He}^{+}$is
(a) $105.8$
(b) $52.9$
(c) $26.5$
(d) $0.0$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 39

In which of the following pairs are both the ions coloured in aqueous solution?
(a) $\mathrm{Sc}^{3+}, \mathrm{Co}^{2+}$
(b) $\mathrm{Ni}^{2+}, \mathrm{Cu}^{+}$
(c) $\mathrm{Ni}^{2+}, \mathrm{Ti}^{3+}$
(d) $\mathrm{Sc}^{3+}, \mathrm{Ti}^{3+}$
(At. no. $\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{Ni}=28, \mathrm{Cu}=29, \mathrm{Co}=27$ )

Preeti Kumari

Numerade Educator

Problem 40

When potassium metal is exposed to violet light
(a) there is no effect
(b) ejection of electron takes place
(c) the absorption of electrons takes place
(d) ejection of some potassium atoms occurs

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 41

The atomic number of $\mathrm{Ni}$ and $\mathrm{Cu}$ are 28 and 29 respectively. The electronic configuration $1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{6} 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6}$
$3 \mathrm{~d}^{10}$ represents
(a) $\mathrm{Cu}^{+}$
(b) $\mathrm{Cu}^{2+}$
(c) $\mathrm{Ni}^{2+}$
(d) $\mathrm{Ni}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 42

Rutherford's experiment, which established the nuclear model of the atom, used a beam of
(a) $\beta$-particles, which impinged on a metal foil and got absorbed
(b) $\gamma$-rays, which impinged on a metal foil and ejected electrons
(c) Helium atoms, which impinged on a metal foil and got scattered
(d) Helium nuclei, which impinged on a metal foil and got scatterd.

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 43

The quantum number $+1 / 2$ and $-1 / 2$ for the electron spin represent
(a) rotation of the electron in clockwise and anticlockwise direction respectively.
(b) rotation of the electron in anti clockwise and clockwise direction respectively.
(c) magnetic moment of the electron pointing up and down respectively.
(d) two quantum mechanical spin states which have no classical analogues.

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 44

The electronic configuration of an element is $1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2}$ $2 p^{6} 3 s^{2} 3 p^{6} 3 d^{5} 4 s^{1}$. This represents
(a) excited state
(b) ground state
(c) cationic form
(d) anionic form

Preeti Kumari

Numerade Educator

Problem 45

The angular momentum (L) of an electron in a Bohr orbit is given as
(a) $L=n h / 2 \pi$
(b) $v[l(l+1) \mathrm{h} / 2 \pi$
(c) $\mathrm{L}=\mathrm{mg} / 2 \pi$
(d) $L=h / 4 \pi$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 46

Which one of the following is the standard for atomic mass?
(a) ${ }_{1} \mathrm{H}^{1}$
(b) ${ }_{6} \mathrm{C}^{12}$
(c) ${ }_{6} \mathrm{C}^{4}$
(d) ${ }_{8} \mathrm{O}^{16}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 47

Which of the following relates to photons both as wave motion and as a stream of particles?
(a) interference
(b) $\mathrm{E}=\mathrm{mc}^{2}$
(c) diffraction
(d) $\mathrm{E}=\mathrm{h} v$

Preeti Kumari

Numerade Educator

Problem 48

Electromagnetic radiation with maximum wavelength is
(a) radiowave
(b) X-ray
(c) infraredt
(d) ultraviolet

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 49

When the $\mathrm{e}^{-}$of a $\mathrm{H}$-atom moves from $\mathrm{n}=4$ to $\mathrm{n}=1$ the number of spectral lines emitted is
(a) 3
(b) 6
(c) 9
(d) 15

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 50

Which set represents the quantum Numbers of 19 th electron in Cr-atom?
(a) $4,0,0,1 / 2$
(b) $4,1,0,1 / 2$
(c) $3,2,2,1 / 2$
(d) $3,2,-2,1 / 2$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 51

The orbital diagram in which both the Pauli's exclusion principle and Hund's rule are violated is

Ajay Singhal

Numerade Educator

Problem 52

The maximum number of $3 \mathrm{~d}$ electrons having $\mathrm{s}=+1 / 2$ are
(a) 10
(b) 5
(c) 14
(d) 7

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 53

The fourth electron of Be atom will have which of the following quantum numbers?
(a) $1,0,0,1 / 2$
(b) $2,0,0,-1 / 2$
(c) $2,1,0,+1 / 2$
(d) $1,1,1,+1 / 2$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 54

The electron density between $1 \mathrm{~s}$ and 2 s orbital is
(a) high
(b) low
(c) zero
(d) none of these

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 55

The Angular momentum of an e- can't be
(a) $\frac{\mathrm{h}}{\pi}$
(b) $\frac{2 h}{2 \pi}$
(c) $\frac{2.5 h}{2 \pi}$
(d) $\frac{0.5 \mathrm{~h}}{\pi}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 56

If the wavelength of an electromagnetic radiation is $2000 \AA$. What is the energy in ergs?
(a) $9.92 \times 10^{-19}$
(b) $9.94 \times 10^{-12}$
(c) $4.97 \times 10^{-12}$
(d) $4.97 \times 10^{-19}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 57

The de Broglie wavelength of the electron in the ground state of hydrogen atom is $[\mathrm{K} . \mathrm{E}=13.6 \mathrm{eV}]$; $\mathrm{leV}=1.602 \times 10^{-19} \mathrm{~J}$
(a) $33.28 \mathrm{~nm}$
(b) $3.328 \mathrm{~nm}$
(c) $0.3328 \mathrm{~nm}$
(d) $0.0332 \mathrm{~nm}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 58

The value of Planck constant is $6.63 \times 10^{-34} \mathrm{Js}$. he velocity of light is $3.0 \times 10^{8} \mathrm{~m} \mathrm{~s}^{-1} .$ which value is closest to the wavelength in nanometres of a quantum of light with frequency of $8 \times 10^{15} \mathrm{~s}^{-1}$ ?
(a) $4 \times 10^{1}$
(b) $3 \times 10^{7}$
(c) $2 \times 10^{-25}$
(d) $5 \times 10^{-18}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 59

The total number of electrons present in all the s orbitals, all the p orbitals and all the d orbitals of cesium ion are respectively
(a) $12,20,22$
(b) $8,22,24$
(c) $10,24,20$
(d) $8,26,10$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 60

The frequency of radiation emitted when the electron falls from $\mathrm{n}=4$ to $\mathrm{n}=1$ in a hydrogen atom will be (Given ionization energy of $\mathrm{H}=2.18 \times 10^{18} \mathrm{~J}$ atom $^{-1}$ and $\left.\mathrm{h}=6.625 \times 10^{-34} \mathrm{Js}\right)$
(a) $1.54 \times 10^{15} \mathrm{~s}^{-1}$
(b) $1.03 \times 10^{15} \mathrm{~s}^{-1}$
(c) $3.08 \times 10^{15} \mathrm{~s}^{-1}$
(d) $2.00 \times 10^{15} \mathrm{~s}^{-1}$

Preeti Kumari

Numerade Educator

Problem 61

Among the following series of transition metal ions, the one where all metal ion have $3 \mathrm{~d}^{2}$ electronic configuration is
(a) $\mathrm{Ti}^{3+}, \mathrm{V}^{2+}, \mathrm{Cr}^{3+}, \mathrm{Mn}^{4+}$
(b) $\mathrm{Ti}^{+}, \mathrm{V}^{4+}, \mathrm{Cr}^{6+}, \mathrm{Mn}^{7+}$
(c) $\mathrm{Ti}^{4+}, \mathrm{V}^{3+}, \mathrm{Cr}^{2+}, \mathrm{Mn}^{3+}$
(d) $\mathrm{Ti}^{2+}, \mathrm{V}^{3+}, \mathrm{Cr}^{4+}, \mathrm{Mn}^{5+}$
(At. wt $\mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24, \mathrm{Mn}=25$ )

Preeti Kumari

Numerade Educator

Problem 62

The relationship between energy $\mathrm{E}$, of the radiation with a wavelength $8000 \AA$ and the energy of the ra diation with a wavelength $16000 \AA$ is
(a) $\mathrm{E}_{1}=2 \mathrm{E}_{2}$
(b) $\mathrm{E}_{1}=4 \mathrm{E}_{2}$
(c) $\mathrm{E}_{1}=6 \mathrm{E}_{2}$
(d) $E_{1}=E_{2}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 63

The atomic numbers of elements $\mathrm{X}, \mathrm{Y}, \mathrm{Z}$ are $19.21$ and 25 respectively. The number of electrons present in the 'M' shells of these elements follow the order
(a) $Z>Y>X$
(b) $\mathrm{X}>\mathrm{Y}>\mathrm{Z}$
(c) $Z>X>Y$
(d) $\mathrm{Y}>\mathrm{Z}>\mathrm{X}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 64

An electron is moving in Bohr's fourth orbit, its de-Broglie wavelength is $X$. What is the circumference of the fourth orbit?
(a) $2 \lambda$
(b) $2 / \lambda$
(c) $3 \lambda$
(d) $4 \lambda$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 65

The correct order of number of unpaired electrons in the ion $\mathrm{Cu}^{2+} \mathrm{Ni}^{2+}, \mathrm{Fe}^{3+}$ and $\mathrm{Cr}^{3+}$ is
(a) $\mathrm{Cu}^{2+}>\mathrm{Ni}^{2+}>\mathrm{Cr}^{3+}>\mathrm{Fe}^{3+}$
(b) $\mathrm{Ni}^{2+}>\mathrm{Cu}^{2+}>\mathrm{Fe}^{3+}>\mathrm{Cr}^{3+}$
(c) $\mathrm{Fe}^{3+}>\mathrm{Cr}^{3+}>\mathrm{Ni}^{2+}>\mathrm{Cu}^{2+}$
(d) $\mathrm{Fe}^{3+}>\mathrm{Cr}^{3+}>\mathrm{Cu}^{2+}>\mathrm{Ni}^{2+}$

Preeti Kumari

Numerade Educator

Problem 66

Find the magnetic moment of a divalent ion in aqueous solution if its atomic number is 25 .
(a) $6.9 \mathrm{~B} . \mathrm{M}$
(b) $5.9 \mathrm{~B} . \mathrm{M}$
(c) $4.9 \mathrm{~B} . \mathrm{M} .$
(d) $3.0 \mathrm{~B} . \mathrm{M}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 67

The magnetic moment of $\mathrm{Cu}^{2+}$ ion is
(a) $2.6$
(b) $2.76$
(c) $1.73$
(d) 0

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 68

Given: the mass of electron is $9.11 \times 10^{-31} \mathrm{~kg}$ Planck constant is $6.626 \times 10^{-34} \mathrm{Js}$, the uncertainty involved in the measurement of velocity within a distance of $0.1 \AA$ is
(a) $5.79 \times 10^{8} \mathrm{~ms}^{-1}$
(b) $5.79 \times 10^{5} \mathrm{~ms}^{-1}$
(c) $5.79 \times 10^{6} \mathrm{~ms}^{-1}$
(d) $5.79 \times 10^{7} \mathrm{~ms}^{-1}$

Preeti Kumari

Numerade Educator

Problem 69

The energy ratio of a photon of wavelength $3000 \AA$ and $6000 \AA$ is
(a) $1: 1$
(b) $2: 1$
(c) $1: 2$
(d) $1: 4$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 70

The energy of second Bohr orbit of the hydrogen atom is $-328 \mathrm{~kJ} \mathrm{~mol}^{-1}$, hence the energy of fourth bohr orbit would be
(a) $-164 \mathrm{~kJ} \mathrm{~mol}^{-1}$
(b) $-41 \mathrm{~kJ} \mathrm{~mol}^{-1}$
(c) $-82 \mathrm{~kJ} \mathrm{~mol}^{-1}$
(d) $-1312 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Preeti Kumari

Numerade Educator

Problem 71

The de Broglie wavelength associated with a particle of mass $10^{-6} \mathrm{~kg}$ moving with a velocity of $10 \mathrm{~ms}^{-1}$ is
(a) $6.63 \times 10^{-7} \mathrm{~m}$
(b) $6.63 \times 10^{-16} \mathrm{~m}$
(c) $6.63 \times 10^{-21} \mathrm{~m}$
(d) $6.63 \times 10^{-29} \mathrm{~m}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 72

In hydrogen atom, energy of first excited state is $-3.4$ $\mathrm{eV}$. The kinetic energy of the same orbit of hydrogen atom would be
(a) $+3.4 \mathrm{eV}$
(b) $+6.8 \mathrm{eV}$
(c) $-13.6 \mathrm{eV}$
(d) $+13.6 \mathrm{eV}$

Preeti Kumari

Numerade Educator

Problem 73

The velocity of an electron in the second shell of hydrogen atom is
(a) $10.94 \times 10^{\circ} \mathrm{ms}^{-1}$
(b) $18.88 \times 10^{6} \mathrm{~ms}^{-1}$
(c) $1.888 \times 10^{6} \mathrm{~ms}^{-1}$
(d) $1.094 \times 10^{6} \mathrm{~ms}^{-1}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 74

Electron energy of a photon is given as: $\Delta \mathrm{E} /$ atom $=3.03 \times 10^{-19} \mathrm{~J}$ atom $^{-1}$ then, the wavelength of the photon is
(a) $6.56 \mathrm{~nm}$
(b) $65.6 \mathrm{~nm}$
(c) $656 \mathrm{~nm}$
(d) $0.656 \mathrm{~nm}$
Given, h (Planck constant) $=6.63 \times 10^{-34} \mathrm{Js} \mathrm{c}$ (velocity of light $)=3.00 \times 10^{8} \mathrm{~ms}^{-1}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 75

If the nitrogen atom has electronic configuration $1 \mathrm{~s}^{7}$, it would have energy lower than that of the normal ground state configuration $1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{3}$, because the electrons would be closer to the nucleus. Yet $1 \mathrm{~s}^{7}$ is not observed because it violates
(a) Heisenberg uncertainty principle
(b) Hund's rule
(c) Pauli's exclusion principle
(d) Bohr postulates of stationary orbits

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 76

Radial nodes present in $3 \mathrm{~s}$ and $2 \mathrm{p}$ orbitals are respectively
(a) 0,2
(b) 2,0
(c) 2,1
(d) 1,2

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 77

The radius of which of the following orbits is same as that of the first Bohr's orbit of hydrogen atom?
(a) $\mathrm{He}^{+}(\mathrm{n}=2)$
(b) $\mathrm{Li}^{2+}(\mathrm{n}=2)$
(c) $\operatorname{Li}^{2+}(\mathrm{n}=3)$
(d) $\mathrm{Be}^{3+}(\mathrm{n}=2)$

Preeti Kumari

Numerade Educator

Problem 78

The wavelength associated with a golf ball weighing $200 \mathrm{~g}$ and moving at a speed of $5 \mathrm{~m} / \mathrm{h}$ is of the order
(a) $10^{-10} \mathrm{~m}$
(b) $10^{-20} \mathrm{~m}$
(c) $10^{-30} \mathrm{~m}$
(d) $10^{-40} \mathrm{~m}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 79

Ground state electronic configuration of nitrogen atom can be represented by
(a) 1 only
(b) 1,2
(c) 1,4
(d) 2,3

Hast Aggarwal

Numerade Educator

Problem 80

Which of the following statement(s) are correct?
(1) the electronic configuration of $\mathrm{Cr}$ is $[\mathrm{Ar}] 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{1}$ (atomic number of $\mathrm{Cr}=24$ )
(2) the magnetic quantum number may have a negative value
(3) in silver atom, 23 electrons have a spin of one type and 24 of the opposite type (atomic number of $\mathrm{Ag}=47$ )
(4) the oxidation state of nitrogen in HN, is $-3$
(a) $1,2,3$
(b) $2,3,4$
(c) 3,4
(d) $1,2,4$

Hast Aggarwal

Numerade Educator

Problem 81

For a d-electron, the orbital angular momentum is
(a) $\sqrt{6 h}$
(b) $\sqrt{2} \mathrm{~h}$
(c) $\mathrm{h}$
(d) $2 \mathrm{~h}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 82

The orbital angular momentum of an electron in $2 \mathrm{~s}$ orbital is
(a) $+\frac{1}{2} \cdot \frac{\mathrm{h}}{2 \pi}$
(b) zero
(c) $\frac{\mathrm{h}}{2 \pi}$
(d) $\sqrt{2} \frac{\mathrm{h}}{2 \pi}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 83

The mass of an electron is $\mathrm{m}$. Its charge is e and it is accelerated from rest through a potential difference $\mathrm{V}$. The velocity acquired by the electron will be
(a) $\sqrt{\mathrm{V} / \mathrm{m}}$
(b) $\sqrt{\mathrm{eV} / \mathrm{m}}$
(c) $\sqrt{2 \mathrm{e} \mathrm{V} / \mathrm{m}}$
(d) none

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 84

An atom $\mathrm{A}$ has the electronic configuration of $1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2}$ $2 \mathrm{p}^{1}$. Atom $\mathrm{B}$ has the electronic configuration of $1 \mathrm{~s}^{2}$ $2 \mathrm{~s}^{2} 2 \mathrm{p}^{1} .$ The empirical formula of the compound obtained from the reaction of $\mathrm{A}$ and $\mathrm{B}$ is
(a) $\mathrm{AB}$
(b) $\mathrm{AB}_{3}$
(c) $\mathrm{A}_{3} \mathrm{~B}_{3}$
(d) $\mathrm{A}_{2} \mathrm{~B}_{6}^{3}$

Preeti Kumari

Numerade Educator

Problem 85

A $600 \mathrm{~W}$ mercury lamp emits monochromatic radiation of wavelength $331.3 \mathrm{~nm}$. How many photons are emitted from the lamp per second?
$\left(\mathrm{h}=6.626 \times 10^{-34} \mathrm{~J} \mathrm{~s} ;\right.$ velocity of light $=3 \times 10^{8} \mathrm{~ms}^{-1}$
(a) $1 \times 10^{19}$
(b) $1 \times 10^{20}$
(c) $1 \times 10^{21}$
(d) $1 \times 10^{23}$

Preeti Kumari

Numerade Educator

Problem 86

The shortest wavelength in hydrogen spectrum of Lyman series when $\mathrm{R}_{H}=109678 \mathrm{~cm}^{-1}$ is
(a) $1002.7 \AA$
(b) $1215.67 \AA$
(c) $1127.30 \mathrm{~A}$
(d) $911.7 \AA$

Preeti Kumari

Numerade Educator

Problem 87

Which electronic level would allow the hydrogen atom
to absorb a photon but not to emit a photon?
(a) $1 \mathrm{~s}$
(b) $2 \mathrm{~s}$
(c) $2 \mathrm{p}$
(d) $3 \mathrm{~s}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 88

Correct set of four quantum numbers for the valence (outermost) electron of rubidium $(\mathrm{Z}=37$ ) is
(a) $5,0,0, \pm 1 / 2$
(b) $6,0,0,+1 / 2$
(c) $5,1,1, \pm 1 / 2$
(d) $5,1,0, \pm 1 / 2$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 89

The increasing order (lowest first) for the values of $\mathrm{e} / \mathrm{m}$ (charge/mass) for electron (e), proton (p), neutron
(n) and alpha particle (a) is
(a) $\mathrm{n}, \mathrm{p}, \mathrm{a}, \mathrm{e}$
(b) $\mathrm{n}, \mathrm{p}, \mathrm{e}, \mathrm{a}$
(c) $\mathrm{n}, \mathrm{a}, \mathrm{p}, \mathrm{e}$
(d) $\mathrm{e}, \mathrm{p}, \mathrm{n}, \mathrm{a}$

Preeti Kumari

Numerade Educator

Problem 90

The ionization energy of hydrogen atom is $13.6 \mathrm{eV}$. What will be the ionization energy of $\mathrm{He}^{+}$?
(a) $13.6 \mathrm{eV}$
(b) $54.4 \mathrm{eV}$
(c) $122.4 \mathrm{eV}$
(d) zero

Preeti Kumari

Numerade Educator

Problem 91

If $S$, be the specific charge $(\mathrm{e} / \mathrm{m})$ of cathode rays and $\mathrm{S}_{2}$ be that of positive rays then which is true?
(a) $\mathrm{S}_{1}=\mathrm{S}_{2}$
(b) $\mathrm{S}_{1}<\mathrm{S}_{2}$
(c) $\mathrm{S}_{1}>\mathrm{S}_{2}$
(d) None of these

Preeti Kumari

Numerade Educator

Problem 92

Predict the total spin in $\mathrm{Ni}^{2+}$ ion
(a) $\pm 5 / 2$
(b) $\pm 3 / 2$
(c) $\pm 1 / 2$
(d) $\pm 1$

Preeti Kumari

Numerade Educator

Problem 93

The orbital diagram in which Aufbau principle is violated is

Ajay Singhal

Numerade Educator

Problem 94

Wave function vs distance from nucleus graph of an orbital is given below:
The number of nodal sphere of this orbital is
(a) 1
(b) 2
(c) 3
(d) 4

Preeti Kumari

Numerade Educator

Problem 95

For the electronic transition from $\mathrm{n}=2 \rightarrow \mathrm{n}=1$, which of the following will produce shortest wave length?
(a) $\mathrm{Li}^{2+}$ ion
(b) D atom
(c) $\mathrm{He}^{+}$ion
(d) $\mathrm{H}$ atom

Preeti Kumari

Numerade Educator

Problem 96

Which of the following curves may represent the speed of the electron in a hydrogen atom as a func tion of the principal quantum number $\mathrm{n}$ ?
(a) $\mathrm{d}$
(b) $\mathrm{c}$
(c) $\mathrm{b}$
(d) a

Preeti Kumari

Numerade Educator

Problem 97

For $\mathrm{n}=2$ the correct set of $\ell, \mathrm{m}$ are
(a) $\ell=2, \mathrm{~m}=-2,-1,0+1,+2$
(b) $\ell=1 \mathrm{~m}=-2,-1,0+1,+2$
(c) $\ell=1 \mathrm{~m}=-1,0,+1$
(d) $\ell=0 \mathrm{~m}=-1,0,+1$

Preeti Kumari

Numerade Educator

Problem 98

Probability of finding the electron $\psi^{2}$ of s orbital doesn't depend upon
(a) azimuthal quantum number.
(b) energy of s orbital
(c) principal quantum number
(d) distance from nucleus (r)

Preeti Kumari

Numerade Educator

Problem 99

The charge cloud of a single electron in a $2 \mathrm{p}_{\mathrm{x}}$ atomic orbital has two lobes of electron density. This means
(a) there is a high probability of locating the electron in a $2 \mathrm{p}_{\mathrm{x}}$ atomic orbital at values of $\mathrm{x}>0$
(b) there is a great probability of finding a p electron right at the nucleus
(c) there is a high probability of locating it values of $x<0$ but no probability at alloy locating if any where in the yz plane along which $x=0$.
(d) both (a) and (c)

Preeti Kumari

Numerade Educator

Problem 100

The wavelength of the de Broglie wave of the electron revolving in the fifth orbit of the hydrogen atom is $\left(\mathrm{r}_{0}\right.$ is the Bohr's radius $=0.529 \mathrm{~A}$ )
(a) $20 \mathrm{r}_{0}$
(b) $(10 \pi) \mathrm{r}_{0}$
(c) $5 \pi \mathrm{r}_{0}$
(d) $15 \pi \mathrm{r}_{\mathrm{d}}$

Preeti Kumari

Numerade Educator

Problem 101

A monoenergetic electron beam with a de Broglie wavelength of $x \AA$ is accelerated till its wavelength is halved. By what factor is its kinetic energy changed?
(a) 8
(b) 6
(c) 4
(d) 3

Preeti Kumari

Numerade Educator

Problem 102

The de Broglie wavelength associated with a ball of mass $1 \mathrm{~kg}$ having a kinetic energy $0.5 \mathrm{~J}$ is
(a) $6.626 \times 10^{-34} \mathrm{~m}$
(b) $13.2 \times 10^{-34} \mathrm{~m}$
(c) $10.38 \times 10^{-21} \mathrm{~m}$
(d) $6.626 \AA$

Preeti Kumari

Numerade Educator

Problem 103

The size of a microscopic particle is one micron and its mass is $6 \times 10^{-13} \mathrm{gm} .$ If its position may be measured to within $0.1 \%$ of its size, the uncertainty in velocity, in $\mathrm{cm} \mathrm{s}^{-1}$, is approximately
(a) $10^{-6} / 3 \pi$
(b) $10^{-7} / 2 \pi$
(c) $10^{-5} / 4 \pi$
(d) $10^{-7} / 4 \pi$

Hast Aggarwal

Numerade Educator

Problem 104

The electrons, identified by quantum numbers $\mathrm{n}$ and $l$ (i) $\mathrm{n}=4 . l=1$ (ii) $\mathrm{n}=4, l=0$ (iii) $\mathrm{n}=3, l=2$ (iv) $\mathrm{n}$
$=3, l=1$ can be placed in order of increasing energy from the lowest to highest as
(a) (iv) $<(i i)<(i i i)<(i)$
(b) (ii) $<(\mathrm{iv})<(\mathrm{i})<(\mathrm{iii})$
(c) (i) $<$ (iii) $<(i i)<$ (iv)
(d) (iii) < (i) < (iv) < (ii)

Preeti Kumari

Numerade Educator

Problem 105

What is the wavelength of the radiation emitted produced in a line in the Lyman series when an electron falls from fourth stationary state in hydrogen atom? $\left(\mathrm{R}_{\mathrm{H}}=1.1 \times 10^{7} \mathrm{~m}^{-1}\right)$
(a) $96.97 \mathrm{~nm}$
(b) $969.7 \mathrm{~nm}$
(c) $9.697 \mathrm{~nm}$
(d) none

Preeti Kumari

Numerade Educator

Problem 106

Rearrange the following (I to IV) in the order of in creasing masses and choose the correct answer from (a), (b), (c), (d). (atomic masses: $\mathrm{N}=14, \mathrm{O}=$ $16, \mathrm{Cu}=63$ ).
I. 1 molecule of oxygen
II. 1 atom of nitrogen
III. $1 \times 10^{10} \mathrm{~g}$ molecular weight of oxygen
IV. $1 \times 10^{-18} \mathrm{~g}$ atomic weight of copper
(a) II $<\mathrm{I}<\mathrm{IV}<\mathrm{III}$
(b) IV < III < II < I
(c) II $<\mathrm{III}<\mathrm{I}<\mathrm{IV}$
(d) III $<$ IV $<\mathrm{I}<\mathrm{II}$

Hast Aggarwal

Numerade Educator

Problem 107

The ionization energy of $\mathrm{He}^{+}$is $19.6 \times 10^{-18} \mathrm{~J}$ atom $^{-1}$. Calculate the energy of the first stationary state of $\mathrm{Li}^{2+}$.
(a) $19.6 \times 10^{-18} \mathrm{~J}$ atom $^{-1}$
(b) $4.41 \times 10^{-18} \mathrm{~J}$ atom $^{-1}$
(c) $19.6 \times 10^{-19} \mathrm{~J}$ atom $^{-1}$
(d) $4.41 \times 10^{-17} \mathrm{~J}$ atom $^{-1}$

Preeti Kumari

Numerade Educator

Problem 108

The masses of photons corresponding to the first lines of the Lyman and the Balmer series of the atomic spectrum of hydrogen are in the ratio of
(a) $4: 1$
(b) $27: 5$
(c) $1: 4$
(d) $5: 27$

Preeti Kumari

Numerade Educator

Problem 109

An X-ray tube is operated at 50,000 volts. The short-wavelength limit of the X-rays produced is
(a) $0.1245 \AA$
(b) $0.3485 \AA$
(c) $0.2485 \AA$
(d) $0.03456 \AA$

Preeti Kumari

Numerade Educator

Problem 110

The ratio of the difference between 2 nd and 3 rd Bohr's orbit energy to that between $3 \mathrm{rd}$ and 4 th orbit energy is
(a) $7 / 20$
(b) $20 / 7$
(c) $27 / 9$
(d) $9 / 27$

Preeti Kumari

Numerade Educator

Problem 111

An electron in a hydrogen atom in its ground state absorbs 1: 50 times as much energy as the minimum required for it to escape from the atom. What is the wavelength of the emitted electron?
(a) $4.7 \AA$
(b) $4.70 \mathrm{pm}$
(c) $6.3 \AA$
(d) $8.4 \AA$

Prem Bijarniya

Numerade Educator

Problem 112

If the radius of the first Bohr orbit is 'a', then de Broglie wavelength of electron in 3 rd orbit is nearly
(a) $2 \pi \mathrm{a}$
(b) $6 \pi$ a
(c) $3 \mathrm{a}$
(d) $\mathrm{a} / 3$

Preeti Kumari

Numerade Educator

Problem 113

If the shortest wavelength of $\mathrm{H}$ atom in Lyman series is 'a', then longest wavelength in Balmer series of $\mathrm{He}^{+}$is
(a) $\mathrm{a} / 4$
(b) $5 \mathrm{a} / 9$
(c) $4 \mathrm{a} / 9$
(d) $9 \mathrm{a} / 5$

Preeti Kumari

Numerade Educator

Problem 114

In hydrogen atom, an orbit has a diameter of about $16.92 \mathrm{~A}$. What is the maximum number of electrons that can be accommodated?
(a) 32
(b) 16
(c) 48
(d) 72

Preeti Kumari

Numerade Educator

Problem 115

Energy levels $\mathrm{A}, \mathrm{B}, \mathrm{C}$ of a certain atom corresponds to increasing values of energy, i.e., $\mathrm{E}_{\mathrm{A}}<\mathrm{E}_{\mathrm{B}}<\mathrm{E}_{c}$. If $\mathrm{X}_{1}, \mathrm{X}_{2}$ and $\mathrm{X}_{3}$ are the wavelengths of radiations corresponding to the transitions $\mathrm{C}$ to $\mathrm{B}, \mathrm{B}$ to $\mathrm{A}$ and $\mathrm{C}$ to A respectively, which of the following statement is correct?
(a) $\mathrm{X}_{1}+\mathrm{X}_{2}+\mathrm{X}_{3}=0$
(b) $\mathrm{X}_{3}=\mathrm{X}_{1}+\mathrm{X}_{2}$
(c) $\mathrm{X}_{3}{ }^{2}=\mathrm{X}_{1}{ }^{2}+\mathrm{X}_{2}{ }^{2}$
(d) $X_{3}=\frac{X_{1} X_{2}}{X_{1}+X_{2}}$

Preeti Kumari

Numerade Educator

Problem 116

A 1000 watt radio transmitter operates at a frequen cy of $880 \mathrm{kc} / \mathrm{sec}$. How many photons per sec does it emit? $\left[\mathrm{h}=6.626 \times 10^{-34} \mathrm{Js}\right]$
(a) $2.51 \times 10^{30}$
(b) $2.27 \times 10^{28}$
(c) $1.72 \times 10^{30}$
(d) $1.77 \times 10^{27}$

Preeti Kumari

Numerade Educator

Problem 117

How many moles of electrons weigh one kilogram? (mass of electron $=9.108 \times 10^{-31} \mathrm{~kg}$, Avogadro number $\left.=6.023 \times 10^{23}\right)$
(a) $6.023 \times 10^{23}$
(b) $1 / 9.108 \times 10^{31}$
(c) $\frac{6.023}{9.108} \times 10^{54}$
(d) $\frac{1}{9.108 \times 6.023} \times 10^{8}$

Preeti Kumari

Numerade Educator

Problem 118

Calculate the wavelength and energy of the radiation emitted for the electronic transition from infinity $(\infty)$ to stationary state first of the hydrogen atom. $\left(\mathrm{R}_{\mathrm{H}}=1.09678 \times 10^{7} \mathrm{~m}^{-1}, \mathrm{~h}=6.6256 \times 10^{-34} \mathrm{Js}\right)$
(a) $2.18 \times 10^{-21} \mathrm{~kJ}$
(b) $3.18 \times 10^{-22} \mathrm{~kJ}$
(c) $1.18 \times 10^{-23} \mathrm{~kJ}$
(d) $2.18 \times 10^{-31} \mathrm{~kJ}$

Prem Bijarniya

Numerade Educator

Problem 119

Some of the following sets of quantum numbers are correct for a $4 \mathrm{~d}$ electron. Which are correct sets?
(a) $4,3,2,+\frac{1}{2}$
(b) $4,2,1,0$
(c) $4,2,-2,+\frac{1}{2}$
(d) $4,2,1,-\frac{1}{2}$

Preeti Kumari

Numerade Educator

Problem 120

$\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{Cl}_{3}(\mathrm{Cr}=24)$ has a magnetic moment of
$3.83$ B.M. The incorrect distribution of 3 d electrons in the chromium of the complex is
(a) $3 \mathrm{~d}_{x y}^{1} 3 \mathrm{~d}_{y z}^{1} 3 \mathrm{~d}^{1}$
(b) $3 \mathrm{~d}_{x y}^{1} 3 \mathrm{~d}_{y z}^{1} 3 \mathrm{~d}^{1} z^{2}$
(c) $3 \mathrm{~d}^{1} 2 \mathrm{~d}^{1} x^{2}-y^{2} 3 \mathrm{~d}^{1} z^{2} 3 \mathrm{~d}^{1}{ }_{x z}$
(d) $3 \mathrm{~d}_{x y}^{1} 3 \mathrm{~d}^{1} x^{2}-y^{2} 3 d_{y z}^{1}$

Preeti Kumari

Numerade Educator

Problem 121

Which of the following statement (s) is /are incorrect?
(a) $3 \mathrm{~s}$ orbital has 2 radical nodes.
(b) Electronic configuration of $\mathrm{Co}^{3+}$ is $4 \mathrm{~s}^{2} 3 \mathrm{~d}^{4}$.
(c) $2 \mathrm{p}$ orbital has 1 radial node.
(d) Node is a region around the nucleus of an atom where probability of finding electron is maximum.

Preeti Kumari

Numerade Educator

Problem 122

Which of the following factors induce larger angle of deflection in Rutherford's scattering experiment?
(a) The initial kinetic energy of striking $\alpha$-particles must be large
(b) The initial kinetic energy of striking $\alpha$-particles must be small
(c) The nucleus to which the $\alpha$-particles are striking must have small atomic number
(d) The nucleus to which the $\alpha$-particles are striking must have high atomic number

Asmita Mehta

Numerade Educator

Problem 123

Energy of level $1,2,3$ of a certain atom corresponds to increasing value of energy $\mathrm{E}_{1}<\mathrm{E}_{2}<\mathrm{E}_{3}$. If $\lambda_{1}, \lambda_{2}$ and $\lambda$ are the wavelength of radiation corresponding to transition $3 \rightarrow 2,2 \rightarrow 1$ and $3 \rightarrow 1$ respectively. Which of following statement is/are correct?
(a) $\frac{1}{\lambda_{2}}=\frac{1}{\lambda_{1}}+\frac{1}{\lambda_{3}}$.
(b) $\lambda_{2}=\frac{\lambda_{1} \lambda_{3}}{\lambda_{1}+\lambda_{2}}$.
(c) $\frac{1}{\lambda_{3}}=\frac{1}{\lambda_{1}}+\frac{1}{\lambda_{2}}$.
(d) $\lambda_{3}=\frac{\lambda_{1} \lambda_{2}}{\lambda_{1}+\lambda_{2}}$.

Preeti Kumari

Numerade Educator

Problem 124

For radial probability distribution curves, which of the following is /are correct?
(a) the number of spherical or radial nodes is equal to $(\mathrm{n}-l-1)$
(b) the number of maxima in $2 \mathrm{~s}$ orbital is two
(c) the number of angular nodes is ' $l$ ".
(d) $3 \mathrm{~d}_{x^{2}}$ has two spherical nodes.

Preeti Kumari

Numerade Educator

Problem 125

In which of the orbital/orbitals radial node and angular nodes are same?
(a) $3 \mathrm{p}$
(b) $4 \mathrm{p}$
(c) $6 \mathrm{f}$
(d) $5 \mathrm{~d}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 126

Four different set of quantum numbers for 4 electrons are given below :
$\mathrm{e}_{1}=4,0,0-1 / 2 ; \mathrm{e}_{2}=3,1,1-1 / 2$
$\mathrm{e}_{3}=3,2,2+1 / 2 ; \mathrm{e}_{4}=3,0,0,+1 / 2$
Then which of the following order of energies of $\mathrm{e}_{1}, \mathrm{e}_{2}$, $\mathrm{e}_{3}$ and $\mathrm{e}_{4}$ are against the quantum rules ?
(a) $\mathrm{e}_{1}>\mathrm{e}_{2}>\mathrm{e}_{3}>\mathrm{e}_{4}$
(b) $\mathrm{e}_{4}>\mathrm{e}_{3}>\mathrm{e}_{2}>\mathrm{e}_{1}$
(c) $\mathrm{e}_{3}>\mathrm{e}_{1}>\mathrm{e}_{2}>\mathrm{e}_{4}$
(d) $e_{2}>e_{3}>e_{4}>e_{1}$

Preeti Kumari

Numerade Educator

Problem 127

Pick out the wrong statements.
(a) $\mathrm{Fe}^{3+}$ ion is more stable than $\mathrm{Fe}^{2+}$ ion in the gaseous state.
(b) For an electron in a $4 \mathrm{p}$-orbital, the quantum numbers are $\mathrm{n}=4, l=1, \mathrm{~m}=2, \mathrm{~s}=+1 / 2$
(c) Angular momentum of 3 s electron is one.
(d) $(\mathrm{n}+l)$ rule is followed for determining the orbital of the lowest energy state.

Rajesh Singh

Numerade Educator

Problem 128

Which of the following statement is/ are correct?
(a) The number of unpaired electrons in both $\mathrm{Fe}^{2+}$ and $\mathrm{Mn}^{2+}$ are five.
(b) In silver atom, 23 electrons have a spin of one type and 24 of the opposite (atomic number of $\mathrm{Ag}=$ 47).
(c) The azimuthal quantum number may have a negative value.
(d) The electronic configuration of $\mathrm{Cr}$ is $[\mathrm{Ar}] 3 \mathrm{~d}^{5} 4 \mathrm{~s}^{\mathrm{l}}$ (atomic number of $\mathrm{Cr}=24$ )

Rajesh Singh

Numerade Educator

Problem 129

Which of the following statements is /are correct?
(a) The energy of an electron is largely determined by its principal quantum number.
(b) The energy of electron in an orbital in the hydrogen atom depends upon the value of principal quantum number only.
(c) The value of principal quantum number for $24^{\text {t }}$ electron is 3 .
(d) The principal quantum number is a measure of the most probable distance of finding the electron around the nucleus

Preeti Kumari

Numerade Educator

Problem 130

The wavelength associated with an electron (mass = $9.11 \times 10^{-31} \mathrm{~kg}$ ) moving with a velocity of $10^{6} \mathrm{~m} \mathrm{~s}^{-1}$ is
$\left(\mathrm{h}=6.625 \times 10^{-34} \mathrm{~J} \mathrm{~s}\right)$
(a) $0.727 \mathrm{~nm}$
(b) $7.27 \mathrm{~nm}$
(c) $727 \mathrm{~nm}$
(d) $7.27 \mathrm{~m}$

Preeti Kumari

Numerade Educator

Problem 131

The de Broglie wave length of a moving particle of mass $1 \mathrm{~g}$ is $6.625 \times 10^{-23} \mathrm{~m}$. The velocity of the particle is
(a) $100 \mathrm{~cm} \mathrm{~s}^{-1}$
(b) $100 \mathrm{~m} \mathrm{~s}^{-1}$
(c) $10 \mathrm{~m} \mathrm{~s}^{-1}$
(d) $1000 \mathrm{~m} \mathrm{~s}^{-1}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 132

Particle A moving with a certain velocity has de Broglie wavelength of $1 \AA$. If the particle B has mass $20 \%$ and velocity $80 \%$ of that of $\mathrm{A}$, the de Broglie wavelength of $\mathrm{B}$ will be
(a) $1.6 \AA$
(b) $16 \AA$
(c) $4.0 \AA$
(d) $6.25 \AA$

Preeti Kumari

Numerade Educator

Problem 133

Which of the following ions has the highest magnetic moment?
(a) $\mathrm{Fe}^{2+}$
(b) $\mathrm{Mn}^{2+}$
(c) $\mathrm{Cr}^{3+}$
(d) $\mathrm{V}^{3+}$

Preeti Kumari

Numerade Educator

Problem 134

Which of the following ions has magnetic moment equal to that of $\mathrm{Ti}^{3+}$
(a) $\mathrm{Ni}^{2+}$
(b) $\mathrm{Co}^{2+}$
(c) $\mathrm{Fe}^{2+}$
(d) $\mathrm{Cu}^{2+}$

Preeti Kumari

Numerade Educator

Problem 135

An ion of a d-block element has magnetic moment 5.92 BM select the ion among the following:
(a) $\mathrm{Sc}^{3+}$
(b) $\mathrm{Zn}^{2+}$
(c) $\mathrm{Mn}^{2+}$
(d) $\mathrm{Cr}^{3+}$

Preeti Kumari

Numerade Educator

Problem 136

Match List I with List II and select the correct answer using the codes given below the lists:
List-I (Metal ions)
]. $\mathrm{Cr}^{3+}$
2. $\mathrm{Fe}^{2+}$
3. $\mathrm{Ni}^{2+}$
4. $\mathrm{Mn}^{2+}$
List-II (Magnetic moment)
(i) $\sqrt{35}$
(ii) $\sqrt{30}$
(iii) $\sqrt{24}$
(iv) $\sqrt{15}$
(v) $\sqrt{8}$

Preeti Kumari

Numerade Educator

Problem 137

Match the following:
List-I
1. Number of values of $' l$ ' for an energy level ............( $(\mathrm{n}-1)$
2. Actual values of ' $l$ ' for a particular type of orbital
3. Number of 'm' values
4. Actual values of 'n' for a particular type of orbital
List-II
(i) $0,1,2$
(ii) $+1 \ldots \ldots . .+2$,
$\quad+1,0,-l$
(iii) $-2 \ldots .-l$
(iv) $\mathrm{n}$

Rajesh Singh

Numerade Educator

Problem 138

Match the following
Column-I
(a) $2 \mathrm{~s}, 3 \mathrm{~s}, 4 \mathrm{~s}, 4 \mathrm{~d}$
(order of increasing energy)
(b) Quantum numbers of $2 \mathrm{~s}^{2}$ electrons
$\begin{array}{cccc}\mathrm{n} & l & \mathrm{~m} & \mathrm{~s} \\ 2 & 0 & 0 & +1 / 2 \\ 2 & 0 & 0 & -1 / 2\end{array}$
Column-II
(p) Bohr
(q) Hund's rule
(r) Pauli's exclusion principle
(s) Aufbau principle
(t) Size of orbit

Rajesh Singh

Numerade Educator

Problem 139

Match the following
Column-I
(a) $2 \mathrm{~s}$
(b) $2 \mathrm{p}$
(c) $3 \mathrm{~s}$
(d) $3 \mathrm{p}$
Column-II
(p) sum of $(\mathrm{n}+1)$ is 3
(q) total number of nodes are two
(r) Only one node
(s) No radial node
(t) No angular node

Rajesh Singh

Numerade Educator

Problem 140

Match the following
Column-I
(a) $[\mathrm{Ar}] 3 \mathrm{~d}^{8} 4 \mathrm{~s}^{2}$
(b) $[\mathrm{Ar}] 3 \mathrm{~d}^{10}$
(c) $[\mathrm{Ar}] 3 \mathrm{~d}^{\mathrm{t}}$
(d) $[\mathrm{Ar}] 3 \mathrm{~d}^{9}$
Column-II
(p) $\mathrm{Cu}^{2+}$
(q) $\mathrm{Zn}^{2+}$
(r) $\mathrm{Ti}^{+3}$
(s) $\mathrm{Cu}^{+}$
(t) $\mathrm{Ni}$

Preeti Kumari

Numerade Educator

Problem 141

An electron absorbs a photon of light of frequency $7.312 \times 10^{14} \mathrm{~s}^{-1}$ in the first excited state of hydrogen and jumps from there to $\mathrm{n}^{\text {th }}$ excited state. The value of $\mathrm{n}$ is

Hast Aggarwal

Numerade Educator

Problem 142

The ground state electronic wave function of hydrogen atom is proportional to $\mathrm{e}^{-r / 2_{0}}$ where $\mathrm{r}$ is the distance from the nucleus and $\mathrm{a}_{0}$ is a constant.

Calculate the relative probability of finding the electron inside a region of volume $1.0 \mathrm{pm}^{3}$, located at the nucleus to a distance of $\mathrm{a}_{0}$ from the nucleus. Report your answer in single digit ignoring any fraction involved . (Given: $\ln 0.14=-2$ )

Bettina Hanlon

Numerade Educator

Problem 143

The maximum number of $4 \mathrm{f}$ electrons having spin quantum number $-1 / 2$ is

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 144

What is the difference in the angular momentum of an electron present in $2 \mathrm{p}$ and that present in $4 \mathrm{p}$ orbital?

Preeti Kumari

Numerade Educator

Problem 145

Find out the number of waves made by a Bohr electron in one complete revolution in its $3^{\text {rd }}$ orbit?

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 146

Calculate the number of nodal planes in the $\mathrm{d}_{x y}$ orbital.

Preeti Kumari

Numerade Educator

Problem 147

Atomic No. of $\mathrm{Fe}=26$; Number of electrons present in $3 \mathrm{~d}$ orbital in $\mathrm{Fe}^{2+}$ ion is

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 148

Hydrogen atoms in the ground state are excited by means of monochromatic radiation of wavelength $970.6 \AA$. How many different lines are possible in the resulting emission spectrum?

Preeti Kumari

Numerade Educator

Problem 149

Due to transition between different energy levels in H-atom, the de-Broglie wavelength of electron is decreased from $16.5 \AA$ to $6.6 \AA$. Maximum number of spectral lines that can be observed for these transitions
are

Prem Bijarniya

Numerade Educator

Problem 150

Total number of isoelectronic species among the following is
$\mathrm{N}^{3-}, \mathrm{Fe}^{3+}, \mathrm{Al}^{3+}, \mathrm{Mg}^{2+}, \mathrm{Ca}^{2+}, \mathrm{Zn}^{2+}, \mathrm{F}^{-}, \mathrm{Be}, \mathrm{Na}^{+}, \mathrm{Ne}$

Preeti Kumari

Numerade Educator

Problem 151

How many electrons are present in Si atom corresponding to $l=1$ ?

Preeti Kumari

Numerade Educator

Problem 152

An ion $\mathrm{Mn}^{a+}$ has the magnetic moment equal to $4.9$
B.M. Find the value of a

Preeti Kumari

Numerade Educator

Problem 153

Energy of H-atom in the ground state is $-3.6 \mathrm{eV}$, hence energy in the second excited state is
(a) $-6.8 \mathrm{eV}$
(b) $-3.4 \mathrm{eV}$
(c) $-1.51 \mathrm{eV}$
(d) $-4.53 \mathrm{eV}$

Preeti Kumari

Numerade Educator

Problem 154

Uncertainty in position of a particle of $25 \mathrm{~g}$ in space is $10^{-5} \mathrm{~m}$. Hence uncertainty in velocity $\left(\mathrm{ms}^{-1}\right)$ is (Planck constant $\mathrm{h}=6.6 \times 10^{-34} \mathrm{Js}$ ) $\quad$
(a) $2.1 \times 10^{-2 \mathrm{~s}}$
(b) $2.1 \times 10^{-34}$
(c) $0.5 \times 10^{-34}$
(d) $5.0 \times 10^{-24}$

Preeti Kumari

Numerade Educator

Problem 155

Which of the following ions has the maximum magnetic moment? $\quad$
(a) $\mathrm{Mn}^{2+}$
(b) $\mathrm{Fe}^{2+}$
(c) $\mathrm{Ti}^{2+}$
(d) $\mathrm{Cr}^{2+}$

Preeti Kumari

Numerade Educator

Problem 156

In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen?
(a) $3 \longrightarrow 2$
(b) $5 \longrightarrow 2$
(c) $4 \longrightarrow 1$
(d) $2 \longrightarrow 5$

Preeti Kumari

Numerade Educator

Problem 157

The de Broglie wavelength of a tennins ball of mass $60 \mathrm{~g}$ moving with a velocity of 10 metres per second is approximately $\mathbf$
(Planck constant $\mathrm{h}=6.63 \times 10^{-31} \mathrm{Js}$ )
(a) $10^{-33} \mathrm{~m}$
(b) $10^{-31} \mathrm{~m}$
(c) $10-16 \mathrm{~m}$
(d) $10^{-25} \mathrm{~m}$

Preeti Kumari

Numerade Educator

Problem 158

The orbital angular momentum for an electron re volving in an orbit is given by $\sqrt{\ell} /(l+1) \mathrm{h} / 2 \pi$. This momentum for an s electron will be given by
(a) $+1 / 2 . \mathrm{h} / 2 \pi$
(b) zero
(c) $h / 2 \pi$
(d) $\sqrt{2} \cdot \mathrm{h} / 2 \pi$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 159

Which one of the following grouping represents a collection of isoelectronic species? (At. numbers $\mathrm{Cs}-55, \mathrm{Br}-35)$
(a) $\mathrm{Na}^{+}, \mathrm{Ca}^{2+}, \mathrm{Mg}^{2+}$
(b) $\mathrm{N}^{3-}, \mathrm{F}^{-} \mathrm{Na}^{+}$
(c) $\mathrm{Be}, \mathrm{Al}^{3+}, \mathrm{Cl}^{-}$
(d) $\mathrm{Ca}^{2+}, \mathrm{Cs}^{+}, \mathrm{Br}$

Preeti Kumari

Numerade Educator

Problem 160

The number of d electrons retained in $\mathrm{Fe}^{2+}$ (At. number of $\mathrm{Fe}=26$ ) ions is
(a) 3
(b) 4
(c) 5
(d) 6

Preeti Kumari

Numerade Educator

Problem 161

Which of the following sets of quantum numbers is correct for an electron in $4 \mathrm{f}$ orbital?
(a) $\mathrm{n}=4, l=3, \mathrm{~m}=+4, \mathrm{~s}=+1 / 2$
(b) $\mathrm{n}=4, l=4, \mathrm{~m}=-4, \mathrm{~s}=-1 / 2$
(c) $\mathrm{n}=4, l=3, \mathrm{~m}=+1, \mathrm{~s}=+1 / 2$
(d) $\mathrm{n}=3, l=2, \mathrm{~m}=-2, \mathrm{~s}=+1 / 2$

Preeti Kumari

Numerade Educator

Problem 162

Consider the ground state of $\mathrm{Cr}$ atom $(\mathrm{Z}=24)$. The numbers of electrons with the azimuthal quantum numbers, $l=1$ and 2 are, respectively $\quad$
(a) 12 and 4
(b) 12 and 5
(c) 16 and 4
(d) 16 and 5

Preeti Kumari

Numerade Educator

Problem 163

The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to station ary state 1 , would be (Rydberg constant $=1.097 \times 10^{7}$
$\left.\mathrm{m}^{-1}\right)$

(a) 9 lnm
(b) $192 \mathrm{~nm}$
(c) $406 \mathrm{~nm}$
(d) $9.1 \times 10^{-8} \mathrm{~nm}$

Preeti Kumari

Numerade Educator

Problem 164

Which one of the following sets of ions represents the collection of isoelectronic species?
(a) $\mathrm{K}+\mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}, \mathrm{Cl}^{-}$
(b) $\mathrm{Na}^{+}, \mathrm{Ca}^{2+}, \mathrm{S} \mathrm{c}^{3+}, \mathrm{F}^{-}$
(c) $\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Mg}^{2+}, \mathrm{Sc}^{3+}$
(d) $\mathrm{Na}^{+} \mathrm{Mg}^{2+}, \mathrm{Al}^{3+}, \mathrm{Cl}$

Preeti Kumari

Numerade Educator

Problem 165

In a multielectron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic field and electric fields?
(a) $\mathrm{n}=1, l=0, \mathrm{~m}=0$
(b) $\mathrm{n}=2, l=0, \mathrm{~m}=0$
(c) $\mathrm{n}=3, l=1, \mathrm{~m}=1$
(d) $\mathrm{n}=3, l=2, \mathrm{~m}=1$
(e) $\mathrm{n}=3, l=2, \mathrm{~m}=0$
(a) $\mathrm{b}$ and $\mathrm{c}$
(b) $\mathrm{d}$ and $\mathrm{e}$
(c) $\mathrm{c}$ and $\mathrm{d}$
(d) a and $\mathrm{b}$

Preeti Kumari

Numerade Educator

Problem 166

Which of the following statements in relation to the hydrogen atom is correct?
(a) $3 \mathrm{~s}$ and $3 \mathrm{p}$ orbitals are of lower energy than $3 \mathrm{~d}$ orbital
(b) $3 \mathrm{p}$ orbital is lower in energy than $3 \mathrm{~d}$ orbital
(c) 3 s orbital is lower in energy than $3 \mathrm{p}$ orbital
(d) $3 \mathrm{~s}, 3 \mathrm{p}$ and $3 \mathrm{~d}$ orbitals all have the same energy

Preeti Kumari

Numerade Educator

Problem 167

Of the following sets which one does not contain iso electronic species?
(a) $\mathrm{PO}_{4}^{3-}, \mathrm{SO}_{4}^{2-}, \mathrm{ClO}_{4}^{-}$
(b) $\mathrm{CN}^{-}, \mathrm{N}_{2}, \mathrm{C}_{2}^{2}$
(c) $\mathrm{SO}_{3}^{2-}, \mathrm{CO}_{3}^{2}-\mathrm{NO}_{3}$
(d) $\mathrm{BO}_{3}^{3-}, \mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-}$

Preeti Kumari

Numerade Educator

Problem 168

According to Bohr theory, the angular momentum of an electron in 5 th orbit is
(a) $25 \mathrm{~h} / \pi$
(b) $1.0 \mathrm{~h} / \pi$
(c) $10 \mathrm{~h} / \pi$
(d) $2.5 \mathrm{~h} / \pi$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 169

Which one of the following sets of ions represents a collection of isoelectronic species?
(a) $\mathrm{K}^{+} \cdot \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}$ (b) $\mathrm{Ba}^{2+}, \mathrm{Sr}^{2+} \mathrm{K}^{+}, \mathrm{Ca}^{2+}$
(c) $\mathrm{N}^{3-}, \mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{S}^{2-}$
(d) $\mathrm{Li}^{+}, \mathrm{Na}^{+}, \mathrm{Mg}^{2+} \mathrm{Ca}^{2+}$

Preeti Kumari

Numerade Educator

Problem 170

Which of the following sets of quantum numbers represents the highest energy of an atom? $\quad$
(a) $\mathrm{n}=3, l=2, m=1, \mathrm{~s}=+1 / 2$
(b) $\mathrm{n}=4, l=0, \mathrm{~m}=0, \mathrm{~s}=+1 / 2$
(c) $\mathrm{n}=3, l=0, \mathrm{~m}=0, \mathrm{~s}=+1 / 2$
(d) $\mathrm{n}=3, l=1, \mathrm{~m}=1, \mathrm{~s}=+1 / 2$

Preeti Kumari

Numerade Educator

Problem 171

Which one of the following constitutes a group of the isoelectronic species? $\quad$
(a) $\mathrm{C}_{2}^{2-}, \mathrm{O}_{2}^{-}, \mathrm{CO}, \mathrm{NO}$
(b) $\mathrm{NO}^{+}, \mathrm{C}^{2}{ }_{2}, \mathrm{C}^{\mathrm{N}-}, \mathrm{N}_{2}$
(c) $\mathrm{CN}^{-}, \mathrm{N} 2, \mathrm{O}_{2}^{2-}, \mathrm{C}_{2}^{\frac{2}{2}}$
(d) $\mathrm{N}_{2}, \mathrm{O}_{2}^{-}, \mathrm{NO}^{+}, \mathrm{CO}$

Preeti Kumari

Numerade Educator

Problem 172

In an atom, an electron is moving with a speed of $600 \mathrm{~m} / \mathrm{s}$ with an accuracy of $0.005 \%$. Certainity with which the position of the electron can be located is $\left(\mathrm{h}=6.6 \times 10^{-34} \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\right.$, mass of electron, $\mathrm{em}=9.1 \mathrm{x}$
$\left.10^{-31} \mathrm{~kg}\right):$
(a) $5.10 \times 10^{-3} \mathrm{~m}$
(b) $1.92 \times 10^{-3} \mathrm{~m}$
(c) $3.84 \times 10^{-3} \mathrm{~m}$
(d) $1.52 \times 10^{-3} \mathrm{~m}$

Preeti Kumari

Numerade Educator

Problem 173

Calculate the wavelength (in monometer) associated with a proton moving at $1.0 \times 10^{3} \mathrm{~ms}^{-1}$ (Mass of proton $=1.67 \times 10^{-27} \mathrm{~kg}$ and $\left.\mathrm{h}=6.63 \times 10^{-34} \mathrm{Js}\right): \quad[\mathbf]$
(a) $0.40 \mathrm{~nm}$
(b) $2.5 \mathrm{~nm}$
(c) $14.0 \mathrm{~nm}$
(d) $0.032 \mathrm{~nm}$

Preeti Kumari

Numerade Educator

Problem 174

Ionization energy of. Het is $19.6 \times 10^{-18} \mathrm{~J}$ atom $^{-1}$. The energy of the first stationary state $(\mathrm{n}=1)$ of $\mathrm{Li}^{2+}$ is
(a) $4.41 \times 10^{-16} \mathrm{~J}$ atom $^{-1}$
(b) $-4.41 \times 10^{-17} \mathrm{~J}$ atom $^{-1}$
(c) $-2.2 \times 10^{-15} \mathrm{~J}$ atom $^{-1}$
(d) $8.82 \times 10^{-17} \mathrm{~J}$ atom $^{-1}$

Prem Bijarniya

Numerade Educator

Problem 175

The energy required to break one mole of $\mathrm{Cl}-\mathrm{Cl}$ bonds in $\mathrm{C}_{12}$ is $242 \mathrm{~kJ} \mathrm{~mol}^{-1}$. the longest wavelength of light capable of breaking a single $\mathrm{Cl}-\mathrm{Cl}$ bond is $\left(\mathrm{c}=3 \times 10^{5} \mathrm{~ms}^{-1}\right.$ and $\mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1} \quad[\mathbf{]$
(a) $594 \mathrm{~nm}$
(b) $640 \mathrm{~nm}$
(c) $700 \mathrm{~nm}$
(d) $494 \mathrm{~nm}$

Preeti Kumari

Numerade Educator

Problem 176

A gas adsorbs a photon of $355 \mathrm{~nm}$ and emits at two wavelengths. If one of the emissions is at $680 \mathrm{~nm}$, the other is at:
(a) $743 \mathrm{~nm}$
(b) $376 \mathrm{~nm}$
(c) $453 \mathrm{~nm}$
(d) $581 \mathrm{~nm}$

Preeti Kumari

Numerade Educator

Problem 177

The electrons identified by quantum numbers $\mathrm{n}$ and $l$
(1) $\mathrm{n}=4, l=0$
(2) $\mathrm{n}=4, l=1$
(3) $\mathrm{n}=3, l=1$
(4) $\mathrm{n}=3, l=2$
can be placed in order of increasing energy as
(a) $4<2<3<1$
(b) $2<4<1<3$
(c) $1<3<2<4$
(d) $3<4<2<1$

Preeti Kumari

Numerade Educator

Problem 178

Energy of an electron is given by, $\mathrm{E}=-2.178 \times 10^{-18}\left(\frac{\mathrm{Z}^{2}}{\mathrm{n}^{2}}\right)$
Wavelength of light required to excite an electron in an hydrogen atom from level $\mathrm{n}=1$ to $\mathrm{n}=2$ will be $\left(\mathrm{h}=6.62 \times 10^{-34} \mathrm{Js}\right.$ and $\left.\mathrm{c}=3.0 \times 10^{\mathrm{s}} \mathrm{ms}^{-1}\right)$
(a) $6.500 \times 10^{-7} \mathrm{~m}$
(b) $8.500 \times 10^{-7} \mathrm{~m}$
(c) $1.214 \times 10^{-7} \mathrm{~m}$
(d) $2.816 \times 10^{-7} \mathrm{~m}$

Preeti Kumari

Numerade Educator

Problem 179

The correct set of four quantum numbers for the valence electrons of rubidium atom $(\mathrm{Z}=37)$ is:
(a) $5,1,1, \frac{1}{2}$
(b) $5,0,1, \frac{1}{2}$
(c) $5,0,0, \frac{1}{2}$
(d) $5,1,0, \frac{1}{2}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 180

Which of the following is the energy of a possible excited state of hydrogen?
(a) $+13.6 \mathrm{eV}$
(b) $-6.8 \mathrm{eV}$
(c) $-3.4 \mathrm{eV}$
(d) $+6.8 \mathrm{eV}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator

Problem 181

A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and $\mathrm{m}$ are charge and mass of an electron, respectively, then the value of $\mathrm{h} / \lambda$ (where $\lambda$ is wavelength associated with electron wave) is given by:

(a) $2 \mathrm{meV}$
(b) $\sqrt{\mathrm{meV}}$
(c) $\sqrt{2 \mathrm{meV}}$
(d) $\mathrm{meV}$

Taniya Khandelwal

Taniya Khandelwal

Numerade Educator