NEET Structure of Atom PYQ practice sheet

12 previous-year NEET Chemistry questions from Structure of Atom, newest papers first. Structure of Atom carries 13 of the Chemistry questions in NEET 2020 to 2026, so this is a good place to test yourself after revising the chapter. Marking: +4 correct, −1 wrong.

1. 1.

   RE-NEET 2026

   Consider the following schematic plots of orbital wavefunction ($\psi_r$) against distance ($r$) from the nucleus. Figure: four plots labelled A, B, C and D. A: a smooth decay from a high value at $r = 0$ towards zero without crossing the axis. B: starts high, crosses the zero line once, goes through a minimum and returns to zero. C: starts high, crosses the zero line, goes through a minimum, crosses zero again, goes through a maximum and returns to zero. D: starts at zero, rises to a maximum, crosses the zero line, goes through a minimum and returns to zero. The figure representing two radial nodes in the orbital is

   • (A)
     A
   • (B)
     B
   • (C)
     C
   • (D)
     D
2. 2.

   NEET 2026

   Match List I with List II. List I (Quantum Numbers $n$, $l$): A. $n=2$, $l=1$; B. $n=4$, $l=0$; C. $n=5$, $l=3$; D. $n=3$, $l=2$ List II (Orbital): I. 3d, II. 2p, III. 4s, IV. 5f Choose the correct answer from the options given below.

   • (A)
     A-II, B-III, C-I, D-IV
   • (B)
     A-I, B-II, C-III, D-IV
   • (C)
     A-II, B-III, C-IV, D-I
   • (D)
     A-IV, B-II, C-III, D-I
3. 3.

   NEET 2026

   A bulb is rated at 150 watt, converting 8% energy into light. If energy of one photon is $4.42\times10^{-19}$ J, how many photons are emitted by the bulb per second?

   • (A)
     $27.2\times10^{19}$
   • (B)
     $1.35\times10^{19}$
   • (C)
     $4.06\times10^{19}$
   • (D)
     $2.71\times10^{19}$
4. 4.

   NEET 2024

   Match List I with List II. List I (Quantum Number): (A) $m_l$, (B) $m_s$, (C) $l$, (D) $n$ List II (Information provided): (I) shape of orbital, (II) size of orbital, (III) orientation of orbital, (IV) orientation of spin of electron Choose the correct answer from the options given below:

   • (A)
     A-III, B-IV, C-II, D-I
   • (B)
     A-I, B-III, C-II, D-IV
   • (C)
     A-II, B-I, C-IV, D-III
   • (D)
     A-III, B-IV, C-I, D-II
5. 5.

   NEET 2024

   The energy of an electron in the ground state ($n=1$) for $\mathrm{He^+}$ ion is $-x$ J, then that for an electron in $n=2$ state for $\mathrm{Be^{3+}}$ ion in J is:

   • (A)
     $-4x$
   • (B)
     $-x$
   • (C)
     $-\dfrac49x$
   • (D)
     $-\dfrac{x}{9}$
6. 6.

   NEET 2023

   Select the correct statements from the following : A. Atoms of all elements are composed of two fundamental particles. B. The mass of the electron is $9.10939\times10^{-31}\ \mathrm{kg}$. C. All the isotopes of a given element show same chemical properties. D. Protons and electrons are collectively known as nucleons. E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter. Choose the correct answer from the options given below :

   • (A)
     B, C and E only
   • (B)
     A, B and C only
   • (C)
     C, D and E only
   • (D)
     A and E only
7. 7.

   NEET 2023

   The relation between $n_m$, ($n_m$ = the number of permissible values of magnetic quantum number ($m$)) for a given value of azimuthal quantum number ($l$), is

   • (A)
     $n_m = l + 2$
   • (B)
     $l = \dfrac{n_m - 1}{2}$
   • (C)
     $l = 2n_m + 1$
   • (D)
     $n_m = 2l^2 + 1$
8. 8.

   NEET 2022

   Identify the incorrect statement from the following.

   • (A)
     The shapes of $d_{xy}, d_{yz}$ and $d_{zx}$ orbitals are similar to each other; and $d_{x^2-y^2}$ and $d_{z^2}$ are similar to each other.
   • (B)
     All the five 5d orbitals are different in size when compared to the respective 4d orbitals.
   • (C)
     All the five 4d orbitals have shapes similar to the respective 3d orbitals.
   • (D)
     In an atom, all the five 3d orbitals are equal in energy in free state.
9. 9.

   NEET 2022

   If the radius of the second Bohr orbit of the $\mathrm{He^+}$ ion is 105.8 pm, what is the radius of the third Bohr orbit of the $\mathrm{Li^{2+}}$ ion?

   • (A)
     158.7 Å
   • (B)
     158.7 pm
   • (C)
     15.87 pm
   • (D)
     1.587 pm
10. 10.

    NEET 2021

    A particular station of All India Radio, New Delhi, broadcasts on a frequency of $1{,}368\ \mathrm{kHz}$ (kilohertz). The wavelength of the electromagnetic radiation emitted by the transmitter is : [speed of light, $c = 3.0\times10^{8}\ \mathrm{ms^{-1}}$]

    • (A)
      $2192\ \mathrm{m}$
    • (B)
      $219.2\ \mathrm{m}$
    • (C)
      $21.92\ \mathrm{cm}$
    • (D)
      $219.3\ \mathrm{m}$
11. 11.

    NEET 2021

    From the following pairs of ions which one is not an iso-electronic pair ?

    • (A)
      $\mathrm{Mn^{2+},\ Fe^{3+}}$
    • (B)
      $\mathrm{Na^{+},\ Mg^{2+}}$
    • (C)
      $\mathrm{Fe^{2+},\ Mn^{2+}}$
    • (D)
      $\mathrm{O^{2-},\ F^{-}}$
12. 12.

    NEET 2020

    The number of protons, neutrons and electrons in $^{175}_{71}\mathrm{Lu}$, respectively, are :

    • (A)
      71, 104 and 71
    • (B)
      104, 71 and 71
    • (C)
      71, 71 and 104
    • (D)
      175, 104 and 71