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Structure of Atom

220 Questions Start JEE Mains Test
All Exams JEE Mains JEE Advanced TS-EAMCET AP-EAPCET BITSAT
2009 Q201 JEE Mains MCQ
14 Mar 2026
Calculate the wavelength (in nanometer) associated with a proton moving at 1.0 x 103 ms−1 (Mass of proton = 1.67 $\times$ 10-27 kg and h = 6.63 $\times$ 10-34 Js) :
A.
0.40 nm
B.
2.5 nm
C.
14.0 nm
D.
0.32 nm
2008 Q202 JEE Mains MCQ
14 Mar 2026
Which one of the following constitutes a group of the isoelectronic species?
A.
$C_2^{2 - }$, $O_2^{-}$, CO, NO
B.
$NO^{+}$, $C_2^{2 - }$, CN-, $N_2$
C.
CN-, $N_2$, $O_2^{2-}$, $C_2^{2 - }$
D.
$N_2$, $O_2^{-}$, $NO^{+}$, CO
2008 Q203 JEE Mains MCQ
14 Mar 2026
The ionization enthalpy of hydrogen atom is 1.312 × 106 J mol−1. The energy required to excite the electron in the atom from n = 1 to n = 2 is
A.
8.51 × 105 J mol−1
B.
6.56 × 105 J mol−1
C.
7.56 × 105 J mol−1
D.
9.84 × 105 J mol−1
2007 Q204 JEE Mains MCQ
14 Mar 2026
Which of the following sets of quantum numbers represents the highest energy of an atom?
A.
n = 3, l = 0, m = 0, s = +1/ 2
B.
n = 3, l = 1, m = 1, s = +1/ 2
C.
n = 3, l = 2, m = 1, s = +1/ 2
D.
n = 4, l = 0, m = 0, s = +1/ 2
2006 Q205 JEE Mains MCQ
14 Mar 2026
Which of the following sets of ions represents a collection of isoelectronic species?
A.
N3-, O2-, F-, S2-
B.
Li+, Na+, Mg2+, Ca2+
C.
K+, Cl-, Ca2+, Sc3+
D.
Ba2+, Sr2+, K+, Ca2+
2006 Q206 JEE Mains MCQ
14 Mar 2026
According to Bohr's theory, the angular momentum of an electron in 5th orbit is
A.
10 $h/\pi$
B.
2.5 $h/\pi$
C.
25 $h/\pi$
D.
1.0 $h/\pi$
2006 Q207 JEE Mains MCQ
14 Mar 2026
Uncertainty in the position of an electron (mass = 9.1 $\times$ 10-31 kg) moving with a velocity 300 ms-1, accurate upto 0.001% will be (h = 6.63 $\times$ 10-34 Js)
A.
1.92 $\times$ 10-2 m
B.
3.84 $\times$ 10-2 m
C.
19.2 $\times$ 10-2 m
D.
5.76 $\times$ 10-2 m
2005 Q208 JEE Mains MCQ
14 Mar 2026
In a multi-electron atom, which of the following orbitals described by the three quantum members will have the same energy in the absence of magnetic and electric fields?
(A) n = 1, l = 0, m = 0
(B) n = 2, l = 0, m = 0
(C) n = 2, l = 1, m = 1
(D) n = 3, l = 2, m = 1
(E) n = 3, l = 2, m = 0
A.
(D) and (E)
B.
(C) and (D)
C.
(B) and (C)
D.
(A) and (B)
2005 Q209 JEE Mains MCQ
14 Mar 2026
Pick out the isoelectronic structure from the following :

$\eqalign{ & \left( i \right)\,\,\,\,\,\,C{H_3}^ + \cr & \left( {ii} \right)\,\,\,\,{H_3}{O^ + } \cr & \left( {iii} \right)\,\,\,N{H_3} \cr & \left( {iv} \right)\,\,\,\,C{H_3}^ - \cr} $
A.
$(i)$ and $(ii)$
B.
$(iii)$ and $(iv)$
C.
$(i)$ and $(iii)$
D.
$(ii), (iii)$ and $(iv)$
2005 Q210 JEE Mains MCQ
14 Mar 2026
Of the following sets which one does NOT contain isoelectronic species?
A.
$BO_3^{3 - }$, $CO_3^{2 - }$, $NO_3^{- }$
B.
$SO_3^{2 - }$, $CO_3^{2 - }$, $NO_3^{-}$
C.
$CN^{- }$, $N_2$, $C_2^{2 - }$
D.
$PO_4^{3 - }$, $SO_4^{2 - }$, $ClO_4^{ - }$
2004 Q211 JEE Mains MCQ
14 Mar 2026
Which of the following sets of quantum numbers is correct for an electron in 4f orbital?
A.
n = 4, l = 3, m = +1, s = + 1/2
B.
n = 4, l = 4, m = -4, s = - 1/2
C.
n = 4, l = 3, m = +4, s = + 1/2
D.
n = 3, l = 2, m = -2, s = + 1/2
2004 Q212 JEE Mains MCQ
14 Mar 2026
Consider the ground state of Cr atom (Z = 24). The number of electrons with the azimuthal quantum numbers, l = 1 and 2 are respectively
A.
16 and 4
B.
12 and 5
C.
12 and 4
D.
16 and 5
2004 Q213 JEE Mains MCQ
14 Mar 2026
The wavelength of the radiation emitted when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 $\times$ 107 m-1)
A.
406 nm
B.
192 nm
C.
91 nm
D.
9.1 $\times$ 10-8 nm
2004 Q214 JEE Mains MCQ
14 Mar 2026
Which one of the following sets of ions represents the collection of isoelectronic species? (Atomic nos. : F = 9, Cl = 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)
A.
K+, Cl-, Mg2+, Sc3+
B.
Na+, Ca2+, Sc3+, F-
C.
K+, Ca2+, Sc3+, Cl-
D.
Na+, Mg2+, Al3+, Cl-
2003 Q215 JEE Mains MCQ
14 Mar 2026
Which one of the following groupings represents a collection of isoelectronic species? (At. nos. : Cs : 55, Br : 35)
A.
N3-, F-, Na+
B.
Be, Al3+, Cl-
C.
Ca2+, Cs+, Br
D.
Na+, Ca2+, Mg2+
2003 Q216 JEE Mains MCQ
14 Mar 2026
The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 meters per second is approximately
A.
10-31 meters
B.
10-16 meters
C.
10-25 meters
D.
10-33 meters
2003 Q217 JEE Mains MCQ
14 Mar 2026
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.
5 $\to$ 2
B.
4 $\to$ 1
C.
2 $\to$ 5
D.
3 $\to$ 2
2003 Q218 JEE Mains MCQ
14 Mar 2026
The orbital angular momentum for an electron revolving in an orbit is given by $\sqrt {l(l + 1)} {h \over {2\pi }}$. This momentum for an s-electron will be given by
A.
zero
B.
${h \over {2\pi }}$
C.
$\sqrt 2 {h \over {2\pi }}$
D.
$ + {1 \over 2}{h \over {2\pi }}$
2002 Q219 JEE Mains MCQ
14 Mar 2026
Uncertainty in position of a minute particle of mass 25 g in space is 10-5 m. What is the uncertainty in its velocity (in ms-1) (h = 6.6 $\times$ 10-34 Js)
A.
2.4 $\times$ 10-34
B.
0.5 $\times$ 10-34
C.
2.1 $\times$ 10-28
D.
0.5 $\times$ 10-23
2002 Q220 JEE Mains MCQ
14 Mar 2026
In a hydrogen atom, if energy of an electron in ground state is -13.6 eV, then that in the 2nd excited state is
A.
-1.51 eV
B.
-3.4 eV
C.
-6.04 eV
D.
-13.6 eV