Atomic Structure: MCQ Test (50 questions)

Question 1 of 50

Rutherford's alpha particle scattering experiment on thin gold foil is responsible for the discovery of which of the following?

Aelectron
BProton
Catomic nucleus
DNeutron

Question 2 of 50

The number of protons in the element ₉₂U²ᶾ⁵ is-

A92
B146
C235
D135

Question 3 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 4 of 50

The number of electrons in an atom of atomic number Z and mass number A is

AZ
BA-Z
CA
DA-Z

Question 5 of 50

The number of neutrons in ₉₂U²ᶾ⁸ will be-

A146
B234
C90
D148

Question 6 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 7 of 50

An atom has a mass number of 23 and an atomic number of 11. Find the number of protons.

A23
B22
C12
D11

Question 8 of 50

Which fundamental particles are present in equal numbers in an atom?

Aprotons and neutrons
Belectrons and protons
Cneutrons and electrons
Delectron, proton and neutron

Question 9 of 50

'Positron' is the antiparticle of what?

Aelectron
BProton
CNeutron
DMason

Question 10 of 50

The uncertainty principle was formulated by-

AEinstein
BHeisenberg
CRutherford
DPaulie

Question 11 of 50

The shape of the nucleus of an atom is-

A10‾⁵ m
B10‾⁹ m
C10.5 m
D10‾¹⁵ m

Question 12 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 13 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 14 of 50

The chemical properties of an element depend on-

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

Question 15 of 50

Who first discovered the wave nature of electrons?

AThomson
BDe Broglie
CRutherford
DBohr

Question 16 of 50

Which one of the following most accurately determines the atomic number of an element?

Anumber of protons
Bnumber of protons and electrons
Cnumber of nucleons
DNumber of ions

Question 17 of 50

The nature of elements can be known by-

Aby electronic configuration
Bby atomic number
Cby atomic mass
DBy atomic weight

Question 18 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 19 of 50

If an atom of an element has 2 protons, 2 neutrons and 2 electrons, then what will be the mass number of that element?

A2
B4
C6
D8

Question 20 of 50

1s², 2s²2p⁶ is the electronic configuration of?

ANa and Ne
BNe and Na⁺
CNe and F
DNa⁺ and F

Question 21 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 22 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 23 of 50

The discoverer of 'meson' is-

APaulie
BChadwick
CYukawa
DThomson

Question 24 of 50

The discoverer of 'neutrino' is-

AAnderson
BPaulie
CYukawa
DGoldstein

Question 25 of 50

The number of core electrons in sodium atom is-

A1
B2
C8
D10

Question 26 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 27 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 28 of 50

An atom of an element has 19 protons and 20 neutrons. Its mass number will be-

A39
B19
C20
D12

Question 29 of 50

What is the number of protons in a negatively charged atom (anion)?

Agreater than the atomic number of the element
Bless than the atomic number of the element
Cmore than the number of electrons in the atom
Dless than the number of electrons in the atom

Question 30 of 50

Who first proposed the 'atomic theory' of matter?

ARutherford
BDalton
CThomson
DNiels Vore

Question 31 of 50

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

A2
B8
C18
D32

Question 32 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 33 of 50

Which of the following statements regarding the properties of neutrons is not correct?

AThe mass of a neutron is approximately equal to the mass of a proton.
BThe charge of a neutron is zero
CNeutron is located inside the atomic nucleus
DNeutrons revolve around the atomic nucleus

Question 34 of 50

The atomic number of element A is 13. The number of valence electrons in it will be-

A0
B1
C2
D3

Question 35 of 50

The principle that "electrons do not pair up until the vacant orbital available for them is filled" is called-

AHund's law
BPauli's law
CAufbau principle
DHeisenberg's principle

Question 36 of 50

Which of the following is a chargeless particle?

Aelectron
BProton
CNeutron
DPositron

Question 37 of 50

The number of electrons in ₁₉K⁴⁰ is-

A18
B19
C20
D40

Question 38 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 39 of 50

Who first successfully determined the charge of an electron?

AThomson
BMillikan
CRutherford
DCoulomb

Question 40 of 50

Which one of the following pairs is a particle-antiparticle pair?

Aelectron positron
Bproton neutron
Cphoton – electron
DNeutron - Neutrino

Question 41 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 42 of 50

The atomic mass of an element is equal to the sum of the numbers of which of the following?

Aonly the number of electrons and protons
Bonly the number of protons and neutrons
Conly the number of electrons and neutrons
DThe number of electrons, protons, and neutrons

Question 43 of 50

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

Aelectron
BProton
CNeutron
Dphoton

Question 44 of 50

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

AMason
BProton
Celectron
DNeutron

Question 45 of 50

The nucleus of a chlorine atom of atomic number 17 and mass number 35 contains-

A18 protons
B18 neutrons
C35 protons
D35 neutrons

Question 46 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 47 of 50

Which of the following particles has 20 neutrons and 18 electrons?

A₁₇C1ᶾ⁷
B₁₈Arᶾ⁸
C₁₉Kᶾ⁹
D₁₆Sᶾ⁶

Question 48 of 50

The electronic configuration of the atom with atomic number 20 is-

A2, 8, 10
B2, 6, 8, 4
C2, 8, 8, 2
D2, 10, 8

Question 49 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 50 of 50

The quantum number that specifies the direction of orientation in space of an orbit is-

Aprincipal quantum number
Borbital quantum number
Cmagnetic quantum number
Dspin quantum number