Atomic Structure: Delve into the Building Blocks of Matter

Question 1

Which of the following is **not** a basic unit of an atom?

Accepted Answer

Meson

Answer

Proton

Answer

Neutron

Answer

Electron

Question 2

The atomic number of an element represents the:

Accepted Answer

Total number of protons in the nucleus

Answer

Total number of neutrons in the nucleus

Answer

Total number of electrons in the nucleus

Answer

Total number of protons and neutrons in the nucleus

Question 3

The mass number of an atom is:

Accepted Answer

Sum of the number of protons and neutrons

Answer

Sum of the number of protons and electrons

Answer

Sum of the number of neutrons and electrons

Answer

Difference between the number of protons and neutrons

Question 4

In a neutral atom, the number of protons:

Accepted Answer

Equals the number of electrons

Answer

Equals the number of neutrons

Answer

Equals the sum of the number of neutrons and electrons

Answer

Is always greater than the number of neutrons

Question 5

Who is credited with the discovery of the electron?

Accepted Answer

J.J. Thomson

Answer

Ernest Rutherford

Answer

James Chadwick

Answer

Niels Bohr

Question 6

The quantum number that determines the shape of an atomic orbital is the:

Accepted Answer

Azimuthal quantum number (l)

Answer

Principal quantum number (n)

Answer

Magnetic quantum number (ml)

Answer

Spin quantum number (ms)

Question 7

Which of the following particles is NOT a fundamental component of an atom?

Accepted Answer

Alpha particle

Answer

Proton

Answer

Neutron

Answer

Electron

Question 8

The atomic number of an element defines the number of:

Accepted Answer

Protons

Answer

Neutrons

Answer

Electrons

Answer

Nucleons

Question 9

The mass number of an atom represents the:

Accepted Answer

Sum of protons and neutrons

Answer

Number of protons only

Answer

Number of neutrons only

Answer

Sum of protons, neutrons, and electrons

Question 10

Which particle carries a negative electrical charge?

Accepted Answer

Electron

Answer

Proton

Answer

Neutron

Answer

Alpha particle

Question 11

The nucleus of an atom consists of:

Accepted Answer

Protons and neutrons

Answer

Protons and electrons

Answer

Neutrons and electrons

Answer

Electrons only

Question 12

An atom with an equal number of protons and electrons is considered to be:

Accepted Answer

Neutral

Answer

Positively charged

Answer

Negatively charged

Answer

Polar

Question 13

Which characteristic describes alpha particles?

Accepted Answer

Small size and high energy

Answer

Small size and low energy

Answer

Large size and high energy

Answer

Large size and low energy

Question 14

Electrons within an atom are organized in:

Accepted Answer

Specific energy levels orbiting the nucleus

Answer

Randomly throughout the nucleus

Answer

Fixed positions within the nucleus

Answer

Orbiting the nucleus without defined energy levels

Question 15

The outermost energy level of an atom is referred to as the:

Accepted Answer

Valence shell

Answer

Core shell

Answer

Inner shell

Answer

Transition shell

Question 16

Which of the following is **not** a fundamental subatomic particle of an atom?

Accepted Answer

Quark

Answer

Proton

Answer

Neutron

Answer

Electron

Question 17

An element has an atomic number of 20. How many protons are in an atom of this element?

Accepted Answer

20

Answer

10

Answer

30

Question 18

How many valence electrons does an atom in Group 15 of the periodic table have?

Accepted Answer

5

Answer

1

Answer

2

Answer

7

Question 19

What is the term used to describe the total number of protons and neutrons in an atom?

Accepted Answer

Mass number

Answer

Atomic number

Question 20

Which of the following is NOT an isotope of carbon?

Accepted Answer

Carbon-16

Answer

Carbon-12

Answer

Carbon-14

Question 21

What is the atomic number of an element that has 10 protons?

Accepted Answer

10

Answer

12

Question 22

Which of the following isotopes is used as a fuel in nuclear reactors?

Accepted Answer

Uranium-235

Answer

Carbon-14

Question 23

Which element within Period 2 has the highest electronegativity?

Accepted Answer

Fluorine

Question 24

What type of bond is formed when atoms share electrons?

Accepted Answer

Covalent bond

Question 25

Which subatomic particle is positively charged and found in the nucleus of an atom?

Accepted Answer

Proton

Answer

Neutron

Answer

Electron

Answer

Quark

Question 26

The mass number of an atom is defined as the:

Accepted Answer

Total number of protons and neutrons

Answer

Number of protons only

Answer

Number of neutrons only

Answer

Number of electrons only

Question 27

Which statement accurately describes isotopes?

Accepted Answer

Isotopes have the same atomic number but different mass numbers.

Answer

Isotopes have different atomic numbers and different mass numbers.

Answer

Isotopes have the same atomic number and the same mass number.

Answer

Isotopes have different numbers of electrons.

Question 28

What is the electron configuration of an oxygen atom (atomic number 8) in its ground state?

Accepted Answer

1s² 2s² 2p⁴

Answer

1s² 2s² 2p²

Answer

1s² 2s² 3p⁴

Answer

1s² 2s³

Question 29

Which element exhibits the highest electronegativity?

Accepted Answer

Fluorine

Answer

Chlorine

Answer

Bromine

Answer

Iodine

Question 30

Which force is responsible for the attraction between protons and electrons?

Accepted Answer

Electrostatic force

Answer

Gravitational force

Answer

Nuclear force

Answer

Magnetic force

Question 31

Which characteristic is associated with a covalent bond?

Accepted Answer

Electrons are shared between atoms.

Answer

Electrons are transferred from one atom to another.

Answer

Ions are formed.

Answer

The bond is typically polar.

Question 32

What is the hybridization of the carbon atom in methane (CH₄)?

Accepted Answer

sp³

Answer

sp

Answer

sp²

Answer

sp³d

Question 33

Which atom has the largest atomic radius?

Accepted Answer

Potassium

Answer

Helium

Answer

Lithium

Answer

Sodium

Question 34

The Pauli exclusion principle states that:

Accepted Answer

No two electrons in an atom can have the same set of quantum numbers.

Answer

The energy of an electron is quantized.

Answer

Electrons occupy orbitals in order of increasing energy.

Answer

The maximum number of electrons in an orbital is two.

Question 35

Identify the orbital shape, orientation relative to the z-axis, and spin of an electron with quantum numbers: n = 3, l = 2, ml = -1, and ms = -1/2

Accepted Answer

p-orbital, z-axis, spin down

Answer

s-orbital, x-axis, spin up

Answer

d-orbital, y-axis, spin down

Answer

f-orbital, z-axis, spin up

Question 36

Niels Bohr's key contribution to the atomic model was:

Accepted Answer

Proposing the concept of energy levels

Answer

Discovering the atomic nucleus

Answer

Determining the atomic numbers of elements

Answer

Developing the wave-particle duality theory

Question 37

Which subatomic particle is NOT found within the nucleus of an atom?

Accepted Answer

Electron

Answer

Proton

Answer

Neutron

Answer

Quark

Question 38

Which subatomic particle carries a positive charge?

Accepted Answer

Proton

Answer

Neutron

Answer

Alpha particle

Answer

Electron

Question 39

What is the definition of atomic number?

Accepted Answer

Number of protons in the nucleus

Answer

Number of electrons in the nucleus

Answer

Number of neutrons in the nucleus

Answer

Total number of protons and neutrons in the nucleus

Question 40

Which of the following is not an isotope of Carbon?

Accepted Answer

Carbon-15

Answer

Carbon-13

Answer

Carbon-14

Answer

Carbon-12

Question 41

What is the electron configuration of a neutral sodium atom?

Accepted Answer

1s²2s²2p⁶3s¹

Answer

1s²2s²2p⁵

Answer

1s<sup>2</sup>2s<sup>1</sup>

Question 42

Describe the shape of an sp³ hybridized orbital

Accepted Answer

Tetrahedral

Answer

Square planar

Answer

Trigonal planar

Answer

Linear

Question 43

Which type of chemical bond is formed by the sharing of electron pairs?

Accepted Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Answer

Ionic bond

Question 44

Which of the following elements has the greatest electronegativity?

Accepted Answer

Fluorine

Answer

Oxygen

Answer

Nitrogen

Answer

Chlorine

Question 45

When an acid reacts with a base, what type of chemical reaction occurs?

Accepted Answer

Neutralization reaction

Answer

Precipitation reaction

Answer

Combustion reaction

Answer

Oxidation-reduction reaction

Question 46

Which subatomic particle is negatively charged and has a negligible mass?

Accepted Answer

Electron

Answer

Neutron

Answer

Proton

Question 47

The atomic number of an element is determined by the number of:

Accepted Answer

Protons

Answer

Neutrons

Answer

Electrons

Question 48

Isotopes of an element have:

Accepted Answer

The same number of protons but different numbers of neutrons.

Answer

The same number of neutrons but different numbers of protons.

Answer

Different numbers of protons and electrons.

Question 49

The mass number of an atom represents the:

Accepted Answer

Total number of protons and neutrons.

Answer

Difference between the number of protons and neutrons.

Answer

Number of electrons in the nucleus.

Question 50

Which of the following is NOT a property of electromagnetic radiation?

Accepted Answer

It has mass.

Answer

It travels at the speed of light.

Answer

It is a form of energy.

Question 51

The energy of electrons in atomic orbitals is:

Accepted Answer

Quantized.

Answer

Proportional to the distance from the nucleus.

Answer

Inversely proportional to the atomic number.

Question 52

Which of the following correctly represents the increasing energy levels of atomic orbitals?

Accepted Answer

1s < 2s < 2p < 3s < 3p < 4s < ...

Answer

2s < 1s < 4p < 3s < 3p < 2p < ...

Answer

1s < 3s < 3p < 2s < 2p < 4s < ...

Question 53

A characteristic of a strong acid is that it:

Accepted Answer

Completely dissociates in water.

Answer

Reacts with bases to form salts.

Answer

Has a pH greater than 7.