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Question 1

What is the Greek meaning of the word ‘atom’?

Answer 1

Indivisible or uncuttable

Question 2

Who first expressed the idea that matter is made of tiny indivisible particles called atoms?

Answer 2

Democritus

Question 3

Who is regarded as the ‘father of atomic theory’?

Answer 3

John Dalton

Question 4

What does Dalton’s atomic theory state about atoms of a particular element?

Answer 4

All atoms of a particular element are identical but differ from atoms of other elements

Question 5

What is the mass number of an atom?

Answer 5

Total number of protons and neutrons

Question 6

What is an isotope?

Answer 6

Atoms of the same element with different masses due to different numbers of neutrons

Question 7

What is the charge and mass of an electron?

Answer 7

Charge: -1, Mass: 0.000549 amu

Question 8

Who discovered the electron?

Answer 8

Sir Joseph John Thomson

Question 9

What is the charge and mass of a proton?

Answer 9

Charge: +1, Mass: 1.00728 amu

Question 10

Who is credited with discovering the proton?

Answer 10

Ernest Rutherford

Question 11

What is the charge and mass of a neutron?

Answer 11

Charge: 0, Mass: 1.00894 amu

Question 12

Who discovered the neutron?

Answer 12

James Chadwick

Question 13

Fill in the blank: The number of protons in the nucleus of an atom determines its _______.

Answer 13

Identity

Question 14

What is the relationship between the number of protons and electrons in a neutral atom?

Answer 14

They are equal

Question 15

What do cations and anions represent?

Answer 15

Cation: positive ion, Anion: negative ion

Question 16

What are the four quantum numbers used to describe electron states?

Answer 16

Principal, Angular momentum, Magnetic, Spin

Question 17

What principle states that electrons fill the lowest available energy levels first?

Answer 17

Aufbau Principle

Question 18

What does Hund’s Rule state about electron distribution in orbitals?

Answer 18

Electrons occupy all orbitals of a given subshell singly before pairing begins

Question 19

What is the Pauli Exclusion Principle?

Answer 19

No two electrons in an atom may have identical sets of four quantum numbers

Question 20

List the three types of subatomic particles.

Answer 20

• Electron
• Proton
• Neutron

Question 21

What is the formula to calculate the number of neutrons in an atom?

Answer 21

N = A - Z (where A is mass number and Z is atomic number)

Question 22

True or False: Isotopes of an element have the same number of protons.

Answer 22

True

Question 23

What is the average atomic mass of magnesium based on its isotopes?

Answer 23

24.30504 amu

Question 24

What is an atomic orbital?

Answer 24

Region in space where there is a significant probability of finding a particular electron

Question 25

What is the principal quantum number represented by 'n'?

Answer 25

The main energy level or shell that an electron occupies

Question 26

What are the four quantum numbers used to describe electrons in an atom?

Answer 26

Principal quantum number (n), angular quantum number (l), magnetic quantum number (ml), spin quantum number (ms)

Question 27

What does the Aufbau Principle state about electron configuration?

Answer 27

Electrons are assigned to orbitals in order of increasing value of (n + l)

Question 28

According to Hund's Rule, how are electrons distributed in orbitals?

Answer 28

Electrons occupy orbitals of equal energy singly before pairing up

Question 29

What is the Pauli Exclusion Principle?

Answer 29

No two electrons in the same atom can have identical sets of quantum numbers

Question 30

What is the maximum number of electrons that can occupy one orbital?

Answer 30

Two electrons

Question 31

How is electron configuration defined?

Answer 31

Assignment of all of the electrons in an atom into specific shells and subshells

Question 32

What does the principal quantum number (n) represent?

Answer 32

The energy level or shell of an electron

Question 33

What are the types of subshells represented by angular quantum number (l)?

Answer 33

s, p, d, f

Question 34

What does the superscript in electron configuration indicate?

Answer 34

The number of electrons in a subshell

Question 35

What is the Periodic Law?

Answer 35

When elements are arranged by increasing atomic number, their physical and chemical properties show a periodic pattern

Question 36

What are the rows in the Periodic Table called?

Answer 36

Periods

Question 37

What are the columns in the Periodic Table called?

Answer 37

Groups or Families

Question 38

What are Noble Gases also known as?

Answer 38

Inert Gases

Question 39

What characterizes Representative Elements in the periodic table?

Answer 39

Their last electron is assigned to an outer shell s or p orbital

Question 40

What are Transition Elements characterized by?

Answer 40

Their electrons filling the d orbital

Question 41

What defines Inner Transition Elements?

Answer 41

Their electrons filling the f orbital

Question 42

What is atomic radius?

Answer 42

The radius of an element

Question 43

How does atomic radius trend in the periodic table?

Answer 43

Increases from top to bottom and decreases from left to right

Question 44

What is ionization energy (IE)?

Answer 44

The energy required to remove an electron from an atom

Question 45

How does ionization energy trend in the periodic table?

Answer 45

Decreases from top to bottom and gradually increases from left to right

Question 46

What is electron affinity?

Answer 46

The amount of energy released or absorbed when an electron is added to an atom

Question 47

What is ionic size?

Answer 47

The size of an atom’s ion

Question 48

What are isoelectronic species?

Answer 48

Atoms or ions that have the same number of electrons and the same electronic configuration

Question 49

What is electronegativity (EN)?

Answer 49

The attractive force of an element for a shared pair of electrons in a molecule

Question 50

How does electronegativity trend in the periodic table?

Answer 50

Increases from left to right and decreases from top to bottom

Question 51

Fill in the blank: No more than _______ electrons can occupy one orbital.

Answer 51

two

Question 52

Fill in the blank: The trend of atomic radius _______ from left to right across a period.

Answer 52

decreases

Question 53

Fill in the blank: The trend of ionization energy _______ from top to bottom in groups.

Answer 53

decreases

Question 54

True or False: Electrons occupy the lowest possible energy sublevels before entering higher sublevels.

Answer 54

True