Chapter 4

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

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

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) \({ }^{16} \mathrm{O}_{\mathrm{g}}\) (b) \({ }^{18} \mathrm{O}_{8}\) (c) \({ }^{18} \mathrm{Ne}_{10}\) (d) \({ }^{16} \mathrm{O}_{8}^{-2}\)

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) \(\mathrm{Zn}^{2+} \mathrm{Cu}^{2+}\)

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 \(\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24\)

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) \(\mathrm{Cu}=[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^{1}\)

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

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

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

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) \(\mathrm{n}=2, l=1, \mathrm{~m}=0, \mathrm{~s}=+1 / 2\)

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) \(\mathrm{Ca}, \mathrm{Mg}, \mathrm{Cl}\)

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

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

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

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

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) \(\mathrm{SO}_{2}, \mathrm{CO}_{2}\)

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

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

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

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) \(\mathrm{Mn}^{2+}, \mathrm{Cu}^{2+}\)

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

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

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

\(l=3\), 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) \(0,+1,+2,+3\)

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) \(\mathrm{Cr}^{3+}, \mathrm{Fe}^{3+}\)

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

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

The correct representation for 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) \((\mathrm{n}-\mathrm{l}) \mathrm{d}^{1-10} \mathrm{~ns}^{2}\)

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) \(\mathrm{V}\) (d) Ti

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

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) \(\mathrm{n}=3, l=1, \mathrm{~m}=-1\)

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) \(\mathrm{Ni}^{2+}, \mathrm{Ti}^{\mathrm{i}}\) (d) \(\mathrm{Sc}^{3+}, \mathrm{Ti}^{3+}\) (At. no. \(\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{Ni}=28, \mathrm{Cu}=29, \mathrm{Co}=27\) )

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

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) \(\mathrm{Ni}\)

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.

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.

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

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) \({ }_{8} \mathrm{O}^{16}\)

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) \(\mathrm{E}=\mathrm{h} v\)

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

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

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

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) \(1,1,1,+1 / 2\)

The electron density between Is and 2 s orbital is (a) high (b) low (c) zero (d) none of these

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) \(4.97 \times 10^{-19}\)

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) \(0.0332 \mathrm{~nm}\)

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) \(5 \times 10^{-18}\)

The total number of electrons present in all the \(\mathrm{s}\) 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) \(8,26,10\)

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 \(h=6.625 \times 10^{-34} \mathrm{Js}\) ) (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) \(2.00 \times 10^{15} \mathrm{~s}^{-1}\)

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 \(\mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24, \mathrm{Mn}=25)\)