Atomic Structure: MCQ Test (50 questions)

Question 1 of 50

"The position and velocity of small particles like electrons cannot be determined simultaneously" is the statement of-

AHeisenberg's uncertainty principle
BPauli's exclusion principle
Cof the Aufbau principle
DDe Broglie's idea of the wave nature of electrons

Question 2 of 50

What is the maximum number of electrons in the N shell?

A2
B8
C18
D32

Question 3 of 50

Which of the following electronic configurations is for metallic elements?

A2, 8
B2, 8, 7
C2, 8, 8
D2, 8, 8, 2

Question 4 of 50

Scattering of α-particles from a thin gold foil indicates the presence of

Aelectrons inside an atom
Bprotons inside an atom
Cthe positively charged nucleus at the center of an atom
Disotopes of gold

Question 5 of 50

An atom has 9 electrons, 9 protons, and 10 neutrons. Its mass number will be:

A9
B10
C18
D19

Question 6 of 50

Which of the following conclusions could not be drawn from Rutherford's α-particle scattering experiment?

AMost of the space in an atom is empty
BThe radius of the atom is approximately 10⁵ times the radius of the nucleus.
CElectrons move in circular paths of constant energy, called orbits
DAlmost all the mass of an atom is in the nucleus

Question 7 of 50

Rutherford's scattering experiment proved the existence of what?

Aatoms in all matter
Belectrons in atoms
CNucleus in atoms
DNeutrons in atoms

Question 8 of 50

The mass number of the nucleus is

Ais always less than its atomic number
Bis always greater than its atomic number
Cis always equal to its atomic number
DSometimes it is greater than its atomic number and sometimes it is equal to it.

Question 9 of 50

What controls the orientation of molecular orbitals?

Aazimuth quantum number
Bspin quantum number
Cmagnetic quantum number
Dprincipal quantum number

Question 10 of 50

An Indian scientist whose name is associated with a specific fundamental particle is-

ARaman
Bboss
CChandrashekhar
DSaha

Question 11 of 50

The atomic number of an element is 35 and it has 18 electrons, then the number of protons in it will be-

A17
B18
C20
D15

Question 12 of 50

The maximum number of electrons that an atom of an element can have in its second orbit is-

A8
B32
C18
D2

Question 13 of 50

When Rutherford bombarded a thin sheet of metal with alpha (α) particles to discover the nucleus, then-

AMost of the alpha particles passed through the metal foil without any emission.
BAll the alpha particles passed through the metal foil.
CMost of the alpha particles are deflected by small angles
DMost of the alpha particles are reflected back.

Question 14 of 50

The atomic number of sodium is 11 and its atomic mass is 23. The number of electrons, neutrons and protons in it will be respectively-

A11, 11, 12
B12, 11, 12
C12, 12, 11
D11, 12, 11

Question 15 of 50

What is the charge on an electron?

A−1.6 X 10‾¹⁹ C
B+ 1.6 X 10‾¹⁹ C
C−1.6 X 10 ¹⁹ C
D+ 1.6 X 10 ¹⁹ C

Question 16 of 50

The difference between the atomic mass and mass number of an atom is called-

Aatomic number
Batomic number
CMass damage
Dnumber of electrons

Question 17 of 50

The number of electrons in ₁₉K⁴⁰ is-

A18
B19
C20
D40

Question 18 of 50

What does the nucleus of a singly ionized carbon atom contain?

A6 protons and 6 neutrons
B5 protons and 6 neutrons
C6 protons, 6 neutrons and 6 electrons
D12 protons, 6 neutrons and 6 electrons

Question 19 of 50

Who discovered 'neutron'?

AJames Chadwick
BErnest Rutherford
CJ.J. Thomson
DJohn Dalton

Question 20 of 50

The magnetic quantum number in the context of the molecule of a chemical element is related to-

ABy orientation
Bby frequency
Cby size
Dby rotation

Question 21 of 50

Which one of the following is not a part of an atom?

Aelectron
BProton
CNeutron
Dphoton

Question 22 of 50

Which of the following electronic structures is that of sodium ion?

A2, 8, 1
B2, 8
C2, 8, 8
D2, 8, 7

Question 23 of 50

Which one of the following statements regarding the atomic weight of an element is most appropriate?

AThe atomic mass of an element is the sum of the protons and neutrons present in the atom of that element.
BThe atomic weight of an element can vary depending on its mass number.
CThe atomic weight of an element is an integer
DAll atoms of an element have the same atomic weight

Question 24 of 50

Which of the following is the maximum number of electrons that can be present in the M shell?

A2
B8
C18
D32

Question 25 of 50

When an electron moves from a higher orbit to a lower orbit, then-

Aenergy is released
BEnergy is absorbed.
Cthe size of the atom decreases
Dnone of these

Question 26 of 50

The effective radius of an atom is-

A10¯⁶m
B10¯¹⁰m
C10¯¹⁴m
D10¯¹⁵m

Question 27 of 50

Atoms are electrically-

Apositively
Bnegatively
Cbipositively
Dindifferently

Question 28 of 50

The scattering of which rays can be used to estimate the size of the nucleus?

Aα-particles
Bβ-particles
Cγ-particles
DX-particle

Question 29 of 50

The four quantum numbers of two electrons in an atom cannot be the same. This law is associated with which of the following scientists?

AHund
BPaulie
CFaraday
DArrhenius

Question 30 of 50

The number of core electrons in sodium atom is-

A1
B2
C8
D10

Question 31 of 50

How many electrons can be present in the outermost orbit of an atom?

A2
B8
C18
D16

Question 32 of 50

The electronic configuration of an atom is 2, 8, 2. The number of valence electrons in it is-

A10
B12
C8
D2

Question 33 of 50

The correct relation between energy (E), momentum (p) and velocity (c) of a photon is-

Ap=Ec²
Bp=Ec
Cp=c/E
Dp=E/c

Question 34 of 50

Which nuclear particle has no mass and no charge, but has spin?

Aelectron
BProton
CNeutrinos
DMason

Question 35 of 50

'Positron' is the antiparticle of what?

Aelectron
BProton
CNeutron
DMason

Question 36 of 50

The positive charge of the nucleus was discovered by-

AThomson
BRutherford
CBohr
DJames Chadwick

Question 37 of 50

Carbon has an atomic number of 6 and an atomic weight of 12. How many protons are in its nucleus?

A6
B12
C18
D0

Question 38 of 50

The chemical nature of an element depends on-

Aon impulse
Bon the electron
Con the valence electron
DOn the proton

Question 39 of 50

If the number of orbits is expressed by n, then the maximum number of electrons in any orbit will be-

An
Bn²
C2n²
D2nᶟ

Question 40 of 50

Who discovered the electron in the year 1897?

AJ. J. Thomson
BT. A. Edison
CNikolas Tesla
DIsaac Newton

Question 41 of 50

Which of the following electronic configurations occurs for metallic elements?

A2,8
B2, 8, 7
C2, 8, 18
D2, 8, 18, 2

Question 42 of 50

The discoverer of 'meson' is-

APaulie
BChadwick
CYukawa
DThomson

Question 43 of 50

Who discovered the 'proton'?

AGoldstein
BChadwick
CThomson
DFaraday

Question 44 of 50

If the third orbit of an atom is the outermost orbit, what is the maximum number of electrons it can hold?

A8
B16
C18
D36

Question 45 of 50

In which of the following particles is the double nature of narrow-wave found?

AMason
BProton
Celectron
DNeutron

Question 46 of 50

The number of protons in the element ₉₂U²ᶾ⁵ is-

A92
B146
C235
D135

Question 47 of 50

The chemical properties of an element depend on-

Aon atomic mass
Bon atomic number
Con the mass number
Don atomic weight

Question 48 of 50

The number of neutrons and protons in the nucleus of ₈₈Ra²²⁶ are respectively-

A138 and 88
B88 and 138
C226 and 88
D88 and 226

Question 49 of 50

The chemical behaviour of an atom depends on its-

Aon the number of protons in the nucleus
Bon the number of neutrons in the nucleus
CThe number of electrons revolving around the nucleus
Don the number of nucleons in the nucleus

Question 50 of 50

Which of the following is the most fundamental characteristic of an element?

Amelting point
Batomic number
CColour
Datomic mass