Atomic Structure: MCQ Test (25 questions)

Question 1 of 25

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 2 of 25

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 3 of 25

Who first discovered the wave nature of electrons?

AThomson
BDe Broglie
CRutherford
DBohr

Question 4 of 25

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 5 of 25

The uncertainty principle was formulated by-

AEinstein
BHeisenberg
CRutherford
DPaulie

Question 6 of 25

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

Amelting point
Batomic number
CColour
Datomic mass

Question 7 of 25

The atomic number of a nucleus is Z and its mass number is M. What will be the number of neutrons in the nucleus?

AM + Z
BM-Z
CM x Z
DM ÷ Z

Question 8 of 25

The total energy of an electron revolving in an atom is-

Acannot be negative
Bcan have any value greater than zero
Ccan never be positive
DIt is always positive.

Question 9 of 25

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 10 of 25

Which of the following electronic configurations occurs for metallic elements?

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

Question 11 of 25

Which of the following particles is negatively charged?

AProton
BNeutron
CPositron
Delectron

Question 12 of 25

The particle that binds the nucleon is-

Aelectron
BPositron
CNeutron
DMason

Question 13 of 25

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

A9
B10
C18
D19

Question 14 of 25

1s², 2s²2p⁶ is the electronic configuration of?

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

Question 15 of 25

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 16 of 25

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

A18 protons
B18 neutrons
C35 protons
D35 neutrons

Question 17 of 25

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 18 of 25

The nucleus of an atom contains the following particles:

Aprotons and neutrons
BElectrons and α-particles
Cprotons and electrons
Delectrons and neutrons

Question 19 of 25

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 20 of 25

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 25

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 22 of 25

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 23 of 25

Who discovered the electron in the year 1897?

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

Question 24 of 25

'Positron' is the antiparticle of what?

Aelectron
BProton
CNeutron
DMason

Question 25 of 25

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

A0
B1
C2
D3