**NEET AIPMT Chemistry Chapter Wise Solutions – Structure of Atom**

Contents

NEET AIPMT Chemistry Chapter Wise SolutionsPhysicsBiology

**1. Which one is the wrong statement? (NEET 2017)**

(a) The uncertainty principle is ΔE x Δt ≥ h/4Π

(b) Half filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.

(c) The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.

(d) de-Broglie’s wavelength is given by

λ=h/mv ,where m = mass of the particle,

v = group velocity of the particle.

**2. How many electrons can fit in the orbital for which n = 3 and l = 1? (NEET-II 2016)**

(a) 2

(b) 6

(c) 10

(d) 14

**3. Which of the following pairs of d-orbitals will have electron density along the axes? (NEET-II 2016)**

(a) d_{z²}, d_{xz}

(b) d_{xz}, d_{yz}

(c) d_{z²}, d_{x²-y²}_{ }

(d) d_{xy} ,d_{x²-y²}_{ }

**4. Two electrons occupying the same orbital are distinguished by (NEET-I 2016)**

(a) azimuthal quantum number

(b) spin quantum number

(c) principal quantum number

(d) magnetic quantum number.

**5. Which is the correct order of increasing energy of the listed orbitals in the atom of titanium? (At. no. Z = 22) (2015)**

(a) 4s 3s 3p 3d

(b) 3s 3p 3d 4s

(c) 3s 3p 4s 3d

(d) 3s 4s 3p 3d

**6. The number of d-electrons in Fe ^{2+} (Z = 26) is not equal to the number of electrons in which one of the following? (2015, Cancelled)**

(a) d-electrons in Fe (Z = 26)

(b)p-electrons in Ne (Z= 10)

(c) s-electrons in Mg (Z = 12)

(d) p-electrons in Cl (Z= 17)

**7. The angular momentum of electron in ‘d’ orbital is equal to (2015, Cancelled)**

(a) 2√3h

(b) O h

(c) √6 h

(d) √2 h

**8. What is the maximum number of orbitals that can be identified with the following quantum numbers?**

** n = 3, l = 1, m _{l} = 0 (2014)**

(a) 1

(b) 2

(c) 3

(d) 4

**9. Calculate the energy in joule corresponding to light of wavelength 45 nm. (Planck’s constant, h = 6.63 x 10 ^{-34} J s, speed of light, c = 3 x 10^{8} m ^{-1}) (2014)**

(a) 6.67 x 10

^{15}

(b) 6.67 x 10

^{11}

(c) 4.42 x 10

^{-15}

(d) 4.42 x 10

^{-18}

**10. Be ^{2+} is isoelectronic with which of the following ions? (2014)**

(a) H

^{+}

(b) Li

^{+}

(c) Na

^{+}

(d) Mg

^{2+}

**11. What is the maximum numbers of electrons that can be associated with the following set of quantum numbers?**

**n= 3, l = 1 and m = -1 (NEET 2013)**

(a) 4

(b) 2

(c) 10

(d) 6

**12. Based on equation E = – 2.178 x 10 ^{-18} J[Z^{2/}n^{2}] certain conclusions are written. Which of them is not correct? (NEET 2013)**

(a) Equation can be used to calculate the change in energy when the electron changes orbit.

(b) For n = 1, the electron has a more negative energy than it does for n = 6 which means that the electron is more loosely bound in the smallest allowed orbit.

(c) The negative sign in equation simply means that the energy of electron bound to the nucleus is lower than it would be if the electrons were at the infinite distance from the nucleus.

(d) Larger the value of n, the larger is the orbit radius.

**13. The value of Planck’s constant is 6.63 x 10 ^{-34} J s. The speed of light is 3 x 10^{17} nm s^{-1}. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of 6 x 10^{15 }s^{-1 ?}(NEET 2013)**

(a) 50

(b) 75

(c) 10

(d) 25

**14. The outer electronic configuration of Gd (At. No. 64) is (Karnataka NEET 2013)**

(a) 4f^{5} 5d^{4} 6s^{1}

(b) 4f^{7} 5d^{1} 6s^{2}

(c) 4f^{3} 5d^{5} 6s^{2}

(d) 4f^{4 }5d^{5 }6s^{1}

**15. According to law of photochemical equivalence the energy absorbed (in ergs/mole) is given as (h = 6.62 x 10 ^{-27} ergs, c = 3 x 10^{10} cm s^{-1}, N_{A} = 6.02 x 10^{-23} mol^{-1}) (Karnataka NEET 2013)**

(a) 1.196 x l0

^{8}/λ

(b)2.859 x 10

^{5}/λ

(c) 2.859 x 10

^{16}/λ

(d)1.196 x 10

^{16}/λ

**16. Maximum number of electrons in a subshell with l = 3 and n = 4 is (2012)**

(a) 14

(b) 16

(c) 10

(d) 12

**17. The correct set of four quantum numbers for the valence electron of rubidium atom (Z= 37) is (2012)**

(a) 5, 1,1,+1/2

(b) 6, 0,0,+1/2

(c) 5, 0,0,+1/2

(d) 5, 1,0,+1/2

**18. The orbital angular momentum of a p-electron is given as (Mains 2012)**

(a)h/√2π

(b)√3 h/ 2π

(c)√3h/2π

(d)√6 h/2π

**19. The total number of atomic orbitals in fourth energy level of an atom is (2011)**

(a) 8

(b) 16

(c) 32

(c) 4

**20. The energies E1 and E2 of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths i.e., λ1, and λ2 will be (2011)**

(a)λl = λ_{2}

(b) λl = 2λ_{2}

(c) λl = 4λ_{2}

(d)λl=1/2λ_{2}

**21. If n = 6, the correct sequence for filling of electrons will be (2011)**

(a) ns—> (n – 2)f —> (n – 1)d —> np

(b) ns—> (n – 1 )d —> (n – 2)f —> np

(c) ns—> (n – 2 )f —>np—> (n – 1)d

(d) ns—> np(n – 1 )d —> (n – 2)f

**22. According to the Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon?(Mains 2011)**

(a) n = 6 to n = 1

(b) n = 5 to n = 4

(c) n = 6 to n = 5

(d) n = 5 to n = 3

**23. A 0.66 kg ball is moving with a speed of 100 m/s. The associated wavelength will be (Mains 2010)**

**(h = 6.6 x 10 ^{-34} J s)**

(a) 6.6 x 10

^{-32}m

(b) 6.6 x l0

^{-34 }m

(c) 1.0 x 10

^{-35}m

(d) 1.0 x 10

^{-32}m

**24. Maximum number of electrons in a subshell of an atom is determined by the “following (2009)**

(a) 2l + 1

(b) 4l – 2

(c) 2n²

(d) 4l+2

**25. Which of the following is not permissible arrangement of electrons in an atom? (2009)**

(a) n = 5,l=3,m = 0, s = +l/2

(b) n = 3, l = 2, m = -3, s = -1/2

(c) n = 3, l = 2, m = -2, s = -1/2

(d) n = 4, l= 0, m = 0, s = -1/2

**26. If uncertainty in position and momentum are equal, then uncertainty in velocity is (2008)**

(a)1/m√h/π

(b)√h/π

(c)1/2m√h/π

(d)√h/2π

**27. The measurement of the electron position is associated with an uncertainty in momentum, which is equal to 1 x 10 ^{-18} g cm s^{-1}. The uncertainty in electron velocity is (mass of an electron is 9 x 10^{-28} g)(Prelims 2008)**

(a) 1 x 10

^{5}cm s

^{-1}

(b) 1 x 10

^{11}cm s

^{-1}

(c) 1 x 10

^{9}cm s

^{-1}

(d) 1 x 10

^{6}cm s

^{-1}

**28. Consider the following sets of quantum numbers: (2007)**

**Which of the following sets of quantum number is not possible?**

(a) (i), (ii), (iii) and (iv)

(b) (ii), (iv) and (v)

(c) (i) and (iii)

(d) (ii), (iii) and (iv).

**29. The orientation of an atomic orbital is governed by (2006)**

(a) principal quantum number

(b) azimuthal quantum number

(c) spin quantum number

(d) magnetic quantum number.

**30. Given : The mass of electron is 9.11 x 10- ^{31}kg, Planck constant is 6.626 x 10-^{34} J s, the uncertainty involved in the measurement of velocity within a distance of 0.1 A is (2006)**

(a) 5.79 x 10

^{5}m s

^{-1}

(b) 5.79 x 10

^{6}m s

^{-1}

(c) 5.79 x 10

^{7}m s

^{-1}

(d) 5.79 x 10

^{8}m s

^{-1}

**31. The energy of second Bohr orbit of the hydrogen atom is -328 kJ mol ^{-1}; hence the energy of fourth Bohr orbit would be (2005) **

(a) – 41 kJ mol

^{-1}

(b) -82 kJ mol

^{-1}

(c) -164 kJ mol

^{-1}

(d) -1312 kJ mol

^{-1}

**32. The frequency of radiation emitted when the electron falls from n = 4 to n = 1 in a hydrogen atom will be (Given ionization energy of H = 2.18 x 10 ^{-18} J atom^{-1} and h = 6.625 x 10^{-34} J s) (2004)**

(a) 1.54 x 10

^{15}s

^{-1}

(b) 1.03 x 1o

^{15}s

^{-1}

(c) 3.08 x 10

^{15}s

^{-1}

(d) 2.00 x 10

^{15}s

^{-1}

**33. The value of Planck’s constant is 6.63 x 10- ^{34} J s. The velocity of light is 3.0 x 10^{8} m s^{-1}. Which value is closest to the wavelength in nanometers of a quantum of light with frequency of 8 x 1o^{15} s^{-1}? (2003)**

(a) 2 x 1o

^{-25}

(b) 5 x 10

^{-18}

(c) 4 x 1o

^{1}

(d) 3 x 10

^{7}

**34. In hydrogen atom, energy of first excited state is -3.4 eV. Then find out K.E. of same orbit of hydrogen atom (2002)**

(a) +3.4 eV

(b) +6.8 eV

(c) -13.6 eV

(d) +13.6 eV

**35. Main axis of a diatomic molecule is z, molecular orbital p _{x} and p_{y} overlap to form which of the following orbitals. (2001)**

(a) π molecular orbital

(b) σ molecular orbital

(c) δ molecular orbital

(d) No bond will form.

**36. The following quantum numbers are possible for how many orbitals : n = 3, l = 2, m = +2 ? (2001)**

(a) 1

(b) 2

(c) 3

(d) 4

**37. For given energy, E = 3.03 x 10 ^{-19} Joules corresponding wavelength is**

**(h = 6.626 x 10**

^{-34}J sec, c = 3 x 1o^{8}m/sec) (2000)(a) 65.6 nm

(b) 6.56 nm

(c) 3.4 nm

(d) 656 nm

**38. Isoelectronic species are (2000)**

(a) CO, CN^{–}, NO+, C_{2}²-

(b) CO^{–}, CN, NO, C_{2}–

(c) CO+,CN+,NO-,C_{2}

(d) CO, CN, NO, C_{2}

**39. The uncertainty in momentum of an electron is 1 x 1o ^{-5} kg m/s. The uncertainty in its position will be (h = 6.62 x 10^{-34} kg m^{2}/s) (1999) **

(a) 5.27 x 10

^{-30}m

(b) 1.05 x 10

^{-26 }m

(c) 1.05 x 10

^{-28}m

(d) 5.25 x 10

^{-28}m

**40. Who modified Bohr’s theory by introducing elliptical orbits for electron path? (1999)**

(a) Rutherford

(b) Thomson

(c) Hund

(d) Sommerfield

**41. The de Broglie wavelength of a particle with mass 1 g and velocity 100 m/s is (1999)**

(a) 6.63 x 10^{-35} m

(b) 6.63 x 10^{-34} m

(c) 6.63 x 10^{-33} m

(d) 6.65 x 10 ^{-35} m

**42. The Bohr orbit radius for the hydrogen atom (n = 1) is approximately 0.530 A. The radius for the first excited state (n = 2) orbit is (in A) (1998)**

(a) 4.77

(b) 1.06

(c) 0.13

(d) 2.12

**43. The position of both, an electron and a helium atom is known within 1.0 nm. Further the momentum of the electron is known within 5.0 x 10 ^{-26} kg m s^{-1}. The minimum uncertainty in the measurement of the momentum of the helium atom is (1998)**

(a) 8.0 x 10

^{-26}kg m s

^{-1}

(b) 80 kg m s

^{-1}

(c) 50 kg m s

^{-1}

(d) 5.0 x 10

^{-26}kg m s

^{-1}

**44. The ion that is isoelectronic with CO is (1997)**

(a) CN^{–}

(b) N_{2}^{+}

(C) O^{2-}

(d) N_{2}

**45. What will be the longest wavelength line in Balmer series of spectrum? (1996)**

(a) 546 nm

(b) 656 nm

(c) 566 nm

(d) 556 nm

**46. In a Bohr’s model of an atom, when an electron jumps from n = 1 to n = 3, how much energy will be emitted or absorbed? (1996)**

(a) 2.389 x 10^{-12} ergs

(b) 0.239 x 10^{-10} ergs

(c) 2.15 x 10^{-11} ergs

(d) 0.1936 x 10^{-10} ergs

**47. Uncertainty in position of an electron (mass = 9.1 x 10 ^{-28} g) moving with a velocity of 3 x 10^{4} cm/s accurate upto 0.001% will be (Use h/(4Π) in uncertainty expression where h = 6.626 x 10^{-27 }erg second) (1995)**

(a) 5.76 cm

(b) 7.68 cm

(c) 1.93cm

(d) 3.84cm

**48.The radius of hydrogen atom in the ground state is 0.53 A. The radius of Li ^{2+} ion (atomic number = 3) in a similar state is (1995)**

(a) 0.53 A

(b) 1.06 A

(c) 0.17 A

(d) 0.265 A

**49. For which of the following sets of four quantum numbers, an electron will have the highest energy? (1994)**

n l m s

(a) 3 2 1 +1/2

(b) 4 2 -1 +1/2

(c) 4 1 0 -1/2

(d) 5 0 0 -1/2

**50. Which one of the following is not isoelectronic with O ^{2-}?**

(a)TI

^{+}

(b)Na

^{+}

(c)N

^{3}

^{+}(d)F

^{–}

**51. Electronic configuration of calcium atom can be written as (1992)**

(a)[Ne]4p²

(b)[Ar]4s²

(c)[Ne]4s²

(d)[Kr]4p²

**52.The energy of the electron in the nth Bohr orbit of hydrogen atom is (1992)**

(a)13.6/n^{4} ev

(b)13.6/n^{3} ev

(c)13.6/n^{2} ev

(d)13.6/n ev

**53.In a given atom no two electrons can have the same values for all the four quantum numbers This is called (1991)**

(a) Hund’s Rule

(b) Aufbau principle

(c) Uncertainty principle

(d) Pauli’s Exclusion principle.

**54. For azimuthal quantum number l = 3, the maximum number of electrons will be (1991)**

(a) 2

(b) 6

(c) 0

(d) 14

**55. The order of filling of electrons in the orbitals of an atom will be(1991)**

(a) 3d, 4s, 4p, 4d, 5s

(b) 4s, 3d, 4p, 5s, 4d

(c) 5s, 4p, 3d, 4d, 5s

(d) 3d,4p, 4s, 4d, 5s

**56. The electronic configuration of Cu (atomic number 29) is (1991)**

(a) 1s^{2}, 2s^{2}2p^{6}, 3s^{2}3p^{6}, 4s^{2}3d^{9}

(b) 1s^{2}, 2s^{2}2p^{6}, 3s^{2}3p^{6}3d^{10}, 4s^{1}

(c) 1s^{2}, 2s^{2}2p^{6}, 3s^{2}3p^{6}, 4s^{2}4p^{6}, 5s^{2}5p^{1}

(d) 1s^{2}, 2s^{2}2p^{6}, 3s^{2}3p^{6}, 4s^{2}4p^{6}3d^{3}

**57. The total number of electrons that can be accommodated in all the orbitals having principal quantum number 2 and azimuthal quantum number 1 are (1990)**

(a) 2

(b) 4

(c) 6

(d) 8

**58. An ion has 18 electrons in the outermost shell, it is (1990)**

(a) Cu^{–}

(b) Th^{4+}

(c) Cs^{+}

(d) K^{+}

**59. Which of the following statements do not form a part of Bohr’s model of hydrogen atom? (1989)**

(a) Energy of the electrons in the orbits are quantized.

(b) The electron in the orbit nearest the nucleus has the lowest energy.

(c) Electrons revolve in different orbits around the nucleus.

(d) The position and velocity of the electrons in the orbit cannot be determined simultaneously.

**60. Number of unpaired electrons in N ^{2+} is/are (1989)**

(a) 2

(b) 0

(c) 1

(d) 3

**61. The maximum number of electrons in a subshell is given by the expression (1989)**

(a) 4l-2

(b) 4l+2

(c) 2l+2

(d) 2n²

**62. The spectrum of He is expected to be similar to that (1988)**

(a) H

(b) Li^{+}

(c) Na

(d) He^{+}

**63. The number of spherical nodes in 3p orbitals are/is (1988)**

(a) one

(b) three

(c) none

(d) two

**64. If r is the radius of the first orbit, the radius of nth orbit of H-atom is given by (1988) **

(a) r_{0}n²

(b) r_{0}n

(c) r_{0/}n

(d) r²_{0}n²

**Answer Key**

### Explanations

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