Atomic Structure Quiz: Test Your Understanding of Atoms

Question 1

Which statement does NOT belong to Dalton's atomic theory?

Accepted Answer

Atoms can be created or destroyed.

Answer

Atoms of the same element have identical properties.

Answer

Atoms of different elements have different properties.

Question 2

The central core of an atom, which contains positively charged particles and neutrally charged particles, is called the:

Accepted Answer

Nucleus

Answer

Electron cloud

Answer

Orbital

Answer

Proton

Question 3

The sum of the number of protons and neutrons in an atom is known as the:

Accepted Answer

Mass number

Answer

Atomic number

Answer

Isotope number

Answer

Electron number

Question 4

Atoms of the same element that have the same atomic number but different mass numbers are called:

Accepted Answer

Isotopes

Answer

Allotropes

Answer

Isomers

Answer

Ions

Question 5

The distribution of electrons in an atom around the nucleus is described by the:

Accepted Answer

Electronic configuration

Answer

Atomic number

Answer

Mass number

Answer

Isotope notation

Question 6

As you move down a group in the periodic table, the atomic radius:

Accepted Answer

Increases

Answer

Decreases

Answer

Remains the same

Answer

Increases then decreases

Question 7

The energy required to remove an electron from an atom is called the:

Accepted Answer

Ionization energy

Answer

Electron affinity

Answer

Dissociation energy

Answer

Bond energy

Question 8

Typically, the radius of an anion is:

Accepted Answer

Larger than the radius of the corresponding neutral atom

Answer

Smaller than the radius of the corresponding neutral atom

Answer

Equal to the radius of the corresponding neutral atom

Answer

Unpredictable

Question 9

Which particle is NOT a fundamental subatomic particle of an atom?

Accepted Answer

Quarks

Answer

Proton

Answer

Electron

Answer

Neutron

Question 10

Which of these particles is NOT a fundamental building block of an atom?

Accepted Answer

Photon

Answer

Proton

Answer

Neutron

Answer

Electron

Question 11

What is the atomic number of an atom?

Accepted Answer

The number of protons in the nucleus

Answer

The number of neutrons in the nucleus

Answer

The number of electrons in the outermost energy level

Answer

The total number of protons and neutrons in the nucleus

Question 12

Which of the following elements has the smallest atomic radius?

Accepted Answer

Helium

Answer

Lithium

Answer

Sodium

Answer

Potassium

Question 13

What is the mass number of an atom?

Accepted Answer

The total number of protons and neutrons in the nucleus

Answer

The number of protons in the nucleus

Answer

The number of neutrons in the nucleus

Answer

The number of electrons in the outermost energy level

Question 14

Which of the following is the most electronegative element?

Accepted Answer

Fluorine

Answer

Chlorine

Answer

Bromine

Answer

Iodine

Question 15

The mass number of an atom is determined by the:

Accepted Answer

Sum of protons and neutrons

Answer

Number of protons

Answer

Number of neutrons

Answer

Sum of protons and electrons

Question 16

Which element has an atomic number of 15?

Accepted Answer

Phosphorus

Answer

Nitrogen

Answer

Oxygen

Answer

Sulfur

Question 17

Isotopes are atoms of the same element that differ in their:

Accepted Answer

Mass numbers

Answer

Atomic numbers

Answer

Number of electrons

Answer

Electronic configurations

Question 18

Which of the following is a noble gas element?

Accepted Answer

Helium

Answer

Sodium

Answer

Chlorine

Answer

Calcium

Question 19

The atomic nucleus contains:

Accepted Answer

Neutrons and protons

Answer

Protons and electrons

Answer

Protons, neutrons, and electrons

Answer

Neutrons, protons, and positrons

Question 20

Which electronic configuration represents a noble gas?

Accepted Answer

1s²2s²2p⁶3s²3p⁶

Answer

1s²2s²2p⁶3s²3p⁵

Answer

1s²2s²2p⁶3s¹

Answer

1s²2s²2p⁴

Question 21

Moving across a period in the periodic table, the atomic radius:

Accepted Answer

Decreases

Answer

Increases

Answer

Remains the same

Answer

Initially increases and then decreases

Question 22

Which element possesses the lowest ionization energy?

Accepted Answer

Sodium

Answer

Magnesium

Answer

Aluminium

Answer

Silicon

Question 23

Which of the following is NOT a postulate of Dalton's atomic theory?

Accepted Answer

Atoms are composed of even smaller particles called electrons and protons.

Answer

Atoms of different elements have different masses and properties.

Answer

Atoms of the same element have identical masses and properties.

Answer

Atoms cannot be created or destroyed.

Question 24

Which subatomic particle has a negative charge and is found outside the nucleus?

Accepted Answer

Electron

Answer

Neutron

Answer

Proton

Answer

Alpha particle

Question 25

What is the electron configuration of the ion Na⁺?

Accepted Answer

1s²2s²2p⁶

Answer

1s²2s²2p⁵

Answer

1s²2s²2p⁴

Answer

1s²2s²

Question 26

Which type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 27

At the center of an atom, the nucleus contains:

Accepted Answer

Protons and neutrons

Answer

Protons only

Answer

Neutrons only

Answer

Protons, neutrons, and electrons

Question 28

Which of the following definitions correctly describes atomic number?

Accepted Answer

The number of protons in an atom

Answer

The number of neutrons in an atom

Answer

The number of electrons in an atom

Answer

The sum of protons and neutrons in an atom

Question 29

Which of the following is true about isotopes of an element?

Accepted Answer

Isotopes have varying numbers of neutrons.

Answer

Isotopes have varying numbers of protons.

Answer

Isotopes have different electron configurations.

Answer

Isotopes have different chemical properties.

Question 30

Among the elements sodium, chlorine, potassium, and calcium, which one has the highest electronegativity?

Accepted Answer

Chlorine

Answer

Sodium

Answer

Potassium

Answer

Calcium

Question 31

Which of these orbitals has the lowest energy?

Accepted Answer

s-orbital

Answer

p-orbital

Answer

d-orbital

Answer

f-orbital

Question 32

Which statement is not part of Dalton's atomic theory?

Accepted Answer

Atoms are indivisible and indestructible.

Answer

Atoms of the same element are identical.

Answer

Atoms combine in simple whole-number ratios to form compounds.

Answer

Different elements have different types of atoms, which combine to form compounds.

Question 33

The atomic number of an element represents the:

Accepted Answer

Number of protons in the nucleus

Answer

Number of neutrons in the nucleus

Answer

Mass number of the element

Answer

Sum of protons and electrons

Question 34

Which of the following elements has the largest atomic radius?

Accepted Answer

Barium

Answer

Beryllium

Answer

Magnesium

Answer

Calcium

Question 35

The nucleus of an atom contains which of the following subatomic particles?

Accepted Answer

Protons and neutrons only

Answer

Protons, neutrons, and electrons

Answer

Neutrons and electrons only

Answer

Protons only

Question 36

What does the atomic number of an element represent?

Accepted Answer

The total number of protons in the nucleus

Answer

The total number of electrons in an atom

Answer

The sum of the number of protons and neutrons in the nucleus

Answer

The number of neutrons in the nucleus

Question 37

Calculate the number of neutrons in an atom of chlorine-37 (Cl-37).

Accepted Answer

20

Answer

54

Answer

37

Answer

17

Question 38

Among the following elements, which has the largest atomic radius?

Accepted Answer

Potassium (K)

Answer

Chlorine (Cl)

Answer

Bromine (Br)

Answer

Sodium (Na)

Question 39

What is the electron configuration of an oxygen (O) atom?

Accepted Answer

1s²2s²2p⁴

Answer

1s²2s¹2p⁵

Answer

1s²2s²2p³

Answer

1s²2s²2p⁶

Question 40

Which subatomic particles are found in the nucleus of an atom?

Accepted Answer

Protons and neutrons

Answer

Neutrons and electrons

Answer

Only protons

Answer

Protons and electrons

Question 41

Which characteristic is common to all isotopes of an element?

Accepted Answer

Atomic number

Answer

Number of neutrons

Answer

Number of electrons

Answer

Mass number

Question 42

Which element has the highest electronegativity?

Accepted Answer

Fluorine (F)

Answer

Lithium (Li)

Answer

Sodium (Na)

Answer

Potassium (K)

Question 43

How is a positively charged ion formed?

Accepted Answer

An atom loses electrons.

Answer

An atom loses protons.

Answer

An atom gains neutrons.

Answer

An atom gains electrons.

Question 44

What is the relationship between atomic number and the number of protons in an atom?

Accepted Answer

The atomic number is equal to the number of protons.

Answer

The atomic number is equal to the number of neutrons.

Answer

The atomic number is equal to the number of electrons.

Question 45

A scientist discovers a new element with 118 protons. What is its atomic number?

Accepted Answer

118

Answer

236

Answer

This information is not determinable.

Answer

118.5

Question 46

Which of the following statements is NOT part of Dalton's Atomic Theory?

Accepted Answer

Atoms are indivisible and cannot be broken down further.

Answer

Atoms of different elements combine in simple whole-number ratios to form compounds.

Answer

Atoms of the same element are identical in mass and properties.

Question 47

What is the charge of a neutron?

Accepted Answer

Neutral

Answer

Negative

Answer

Positive

Answer

Variable

Question 48

An atom of chlorine has 17 protons and 18 neutrons. What is its mass number?

Accepted Answer

35

Answer

34

Answer

17

Answer

18

Question 49

Two isotopes of an element have the same:

Accepted Answer

Atomic number

Answer

Number of neutrons

Answer

Mass number

Answer

Number of electrons

Question 50

What is the electronic configuration of an atom of nitrogen (atomic number 7)?

Accepted Answer

1s² 2s² 2p³

Answer

1s² 2s² 2p⁶

Answer

1s² 2s² 2p⁴

Answer

1s² 2s² 2p²

Question 51

Which of the following elements has the largest atomic radius?

Accepted Answer

Sodium (Na)

Answer

Chlorine (Cl)

Answer

Fluorine (F)

Answer

Oxygen (O)

Question 52

A neutral atom of potassium has 19 protons. How many electrons does it have?

Accepted Answer

19

Answer

39

Answer

18

Answer

20

Question 53

Which of the following is NOT a factor that affects ionization energy?

Accepted Answer

The number of isotopes of the element.

Answer

The shielding effect of inner electrons.

Answer

The nuclear charge.

Answer

The distance of the outermost electron from the nucleus.

Question 54

Two atoms of the same element that differ in their number of neutrons are called:

Accepted Answer

Isotopes

Answer

Allotropes

Answer

Isomers

Answer

Ions