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KEAM SERIES
Chemistry

Structure Of Atom

19 previous year questions.

Volume: 19 Ques
Yield: Medium

High-Yield Trend

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Chapter Questions
19 MCQs

01
PYQ 2019
medium
chemistry ID: keam-201
Maximum number of photons emitted by a bulb capable of producing monochromatic light of wavelength is ..........., if and is supplied for one hour.
1
2
3
4
02
PYQ 2022
medium
chemistry ID: keam-202
A particle of mass 6.6\times 10-31kg is moving with a velocity of 1\times 107ms-1. The de Broglie wavelength (in A) associated with the particle, is (h=6.6\times 10-34 Js)
1
1
2
10
3
5
4
2
5
4
03
PYQ 2022
hard
chemistry ID: keam-202
A di-negative ion of the element X consists of 10 electrons and 8 neutrons. A dipositive ion of the element Y consists of 12 protons. The number of neutrons in Y is 1.5 times the number of electrons in atom X. Then the mass numbers of X and Y would be in the ratio
1
1:2
2
2:3
3
3:2
4
2:5
5
1:3
04
PYQ 2023
medium
chemistry ID: keam-202
Which of the following statements is WRONG?
1

The bond order of He2is zero;so He2,molecule is unstable.

2

Li2 molecule is diamagnetic.

3

O2 molecule contains two unpaired electron and is paramagnetic.

4

C2 molecule is paramagnetic in vapour phase.

5

H2 molecule has no unpaired electrons.

05
PYQ 2023
medium
chemistry ID: keam-202
Which of the following statement cannot be explained by the proposals of Dalton's atomic theory?
1

Reorganisation of atoms in chemical reactions

2

ldentical properties of all atoms of given element

3

The reason for combining of atoms

4

Formation of compounds from the combination of elements in a fixed ratio

5

Matter consists of individual atoms

06
PYQ 2025
medium
chemistry ID: keam-202
Which of the following is correct about the stability of half-filled and completely filled subshells?
(i) Relatively small shielding
(ii) Larger coulombic repulsion energy
(iii) Smaller exchange energy
(iv) Smaller coulombic repulsion energy
(v) Larger exchange energy
1
(i), (ii) and (iii)
2
(i), (iii) and (v)
3
(i), (iv) and (v)
4
(ii), (iii) and (v)
5
(i), (ii) and (iv)
07
PYQ 2025
medium
chemistry ID: keam-202
Which of the following have a complete octet?
1
BeCl
2
BF
3
SnCl
4
LiCl
08
PYQ 2025
medium
chemistry ID: keam-202
Which of the following is diamagnetic?
1
[MnCl ]
2
[Fe(CN) ]
3
[Co(C O ) ]
4
[FeF ]
09
PYQ 2025
medium
chemistry ID: keam-202
Properties of canal rays:
1
They are positively charged.
2
They are negatively charged.
3
They travel in straight lines.
4
They have no mass.
10
PYQ 2025
medium
chemistry ID: keam-202
The carboxylic acid used widely in the leather industry is?
1
Acetic acid
2
Formic acid
3
Butyric acid
4
Propionic acid
11
PYQ 2025
medium
chemistry ID: keam-202
IUPAC name of C H is:
1
Hexane
2
Cyclohexane
3
Heptane
4
Octane
12
PYQ 2026
medium
chemistry ID: keam-202
Which of the following set of compounds does not follow octet rule?}
1
and
2
and
3
and
4
and
5
and
13
PYQ 2026
medium
chemistry ID: keam-202
Which of the following statement is NOT the postulate of VSEPR theory?}
1
Where two or more resonance structures can represent a molecule, the VSEPR model is not applicable to any such structure.
2
A multiple bond is treated as if it is a single electron pair and the two or three electron pairs of a multiple bond are treated as a single super pair.
3
The shape of a molecule depends upon the number of valence shell electron pairs around the central atom.
4
Pairs of electrons in the valence shell repel one another since their electron clouds are negatively charged.
5
The valence shell is taken as a sphere with the electron pairs localising on the spherical surface at maximum distance from one another.
14
PYQ 2026
medium
chemistry ID: keam-202
The number and type of bonds between nitrogen and three oxygen atoms in by Lewis representation is}
1
one pi ( ) and 3 sigma ( ) bonds
2
one pi ( ) and 2 sigma ( ) bonds
3
two pi ( ) and 3 sigma ( ) bonds
4
one pi ( ) and 4 sigma ( ) bonds
5
two pi ( ) and 2 sigma ( ) bonds
15
PYQ 2026
medium
chemistry ID: keam-202
The correct increasing order of the ionic radii of the isoelectronic species and is}
1

2

3

4

5
16
PYQ 2026
medium
chemistry ID: keam-202
The set of elements which has exceptional electronic configurations not obeying Aufbau principle is}
1
K, Ca, Cr \& Cu
2
Ca, Cr, Nb \& Cu
3
Ca, Cr, Ag \& Cu
4
Cr, Cu, Ag \& Ru
5
Na, Rh, Cr \& Cu
17
PYQ 2026
medium
chemistry ID: keam-202
Which of the following ions are isoelectronic?
1
2
3
4
5
18
PYQ 2026
medium
chemistry ID: keam-202
The correct increasing order of number of electrons around the central atom in the following molecules is
1
2
3
4
5
19
PYQ 2026
medium
chemistry ID: keam-202
An odd electron molecule among the following is (2015)
1
CO
2
SO
3
CO
4
NO
5
O

About Structure Of Atom - KEAM

Structure Of Atom is a vital chapter for KEAM aspirants. Mastering the concepts covered in this chapter is essential for securing a top rank.

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