4. Atomic Structure

Question 1

What are the three subatomic particles?

Answer 1

Protons, neutrons, electrons

Question 2

Where are protons and neutrons located in the atom?

Answer 2

In the nucleus

Question 3

Where are electrons found in the atom?

Answer 3

In orbitals around the nucleus

Question 4

What is the relative charge of a proton, neutron, and electron?

Answer 4

+1, 0, -1

Question 5

What is the relative mass of protons, neutrons, and electrons?

Answer 5

1, 1, 1/1840

Question 6

What is an isotope?

Answer 6

Atoms with the same number of protons but different numbers of neutrons

Question 7

What is the atomic number?

Answer 7

The number of protons in an atom

Question 8

What is the mass number?

Answer 8

The total number of protons and neutrons in an atom

Question 9

What defines an ion?

Answer 9

Atoms or molecules with a net electric charge due to loss or gain of electrons

Question 10

How do isotopes differ in physical and chemical properties?

Answer 10

Same chemical properties, different physical properties

Question 11

What is the quantum mechanical atomic model based on?

Answer 11

Probability of finding an electron in a specific region around the nucleus

Question 12

What determines the energy level of an electron in an atom?

Answer 12

Principal quantum number (n)

Question 13

What is the shape of an s orbital?

Answer 13

Spherical

Question 14

How many electrons can occupy a single orbital?

Answer 14

2

Question 15

What is Hund’s Rule?

Answer 15

Electrons fill orbitals singly before pairing

Question 16

What is the Pauli Exclusion Principle?

Answer 16

No two electrons can have the same set of quantum numbers

Question 17

Which orbitals fill first, 4s or 3d?

Answer 17

4s fills before 3d

Question 18

How does the energy of orbitals change with increasing n?

Answer 18

Energy increases with increasing n

Question 19

What is ionisation energy?

Answer 19

The energy required to remove one mole of electrons from one mole of gaseous atoms

Question 20

What factors affect ionisation energy?

Answer 20

Nuclear charge, shielding, and distance from the nucleus

Question 21

What trend is observed in ionisation energy across a period?

Answer 21

Increases across a period

Question 22

What trend is observed in ionisation energy down a group?

Answer 22

Decreases down a group

Question 23

Why is the 1st ionisation energy of Al lower than Mg?

Answer 23

The 3p electron in Al is higher in energy than the 3s electron in Mg

Question 24

What causes the lower 1st ionisation energy of S compared to P?

Answer 24

Inter-electron repulsion between paired electrons in S’s 3p orbital

Question 25

What is successive ionisation energy?

Answer 25

The energy required to remove each electron in turn from an atom

Question 26

How is group number deduced from ionisation energy data?

Answer 26

By identifying the number of electrons in the outermost shell from large increases in ionisation energy

Question 27

What is the electron configuration of Ne?

Answer 27

1s 2s 2p?

Question 28

What is the electron configuration of Ca??

Answer 28

1s 2s 2p? 3s 3p?

Question 29

What are isoelectronic species?

Answer 29

Atoms and ions with the same number of electrons and identical electron configurations

Question 30

What is effective nuclear charge?

Answer 30

The net positive charge experienced by valence electrons

Question 31

What effect does increased shielding have on ionisation energy?

Answer 31

Decreases ionisation energy

Question 32

How does atomic radius change across a period?

Answer 32

Decreases across a period

Question 33

How does atomic radius change down a group?

Answer 33

Increases down a group

Question 34

What is the trend in electronegativity across a period?

Answer 34

Increases across a period

Question 35

What is the trend in electronegativity down a group?

Answer 35

Decreases down a group

Question 36

What is electron affinity?

Answer 36

The energy change when an electron is added to a neutral atom in the gas phase

Question 37

What happens to electron affinity across a period?

Answer 37

Becomes more negative (increases)

Question 38

What happens to electron affinity down a group?

Answer 38

Becomes less negative (decreases)

Question 39

Why do noble gases have high ionisation energies?

Answer 39

Full valence shells and strong nuclear attraction to electrons

Question 40

What is the difference between a ground state and an excited state?

Answer 40

Ground state is the lowest energy configuration, excited state occurs when electrons occupy higher energy levels