Topic 1 - Atomic Structure

Question 1

What are the sub-atomic particles that make up an atom?

Answer 1

Protons, electrons, and neutrons.

Question 2

What are the charges and masses of all the sub-atomic particles?

Answer 2

Protons: 1+, 1
Electrons: 1-, 1/1836
Neutrons: 0, 1

Question 3

What is an ion?

Answer 3

An ion is a charged particle.

Question 4

What is an isotope?

Answer 4

An element with the same number of protons but a different number of neutrons.

Question 5

What is a free radical?

Answer 5

A species with one or more unpaired electrons. E.g. Cl*

Question 6

How is a free radical represented?

Answer 6

With a dot.

Question 7

What are the different types of orbitals?

Answer 7

s, p, d, f

Question 8

What is an s-orbital?

Answer 8

The first orbital in the periodic table found in groups 1 & 2. It has 1 orbital and can hold 2 electrons.

Question 9

What is a p-orbital?

Answer 9

The second orbital in the periodic table found in groups 13-18. It has 3 orbitals and can hold 6 electrons.

Question 10

What is a d-orbital?

Answer 10

The third orbital in the periodic table found in groups 3-12. It has 5 orbitals and can hold 10 electrons.

Question 11

What is a f-orbital?

Answer 11

The fourth orbital in the periodic table found in the lanthanoids and actinoids. It has 7 orbitals and can hold 14 electrons.

Question 12

Which two elements are not found in groups 1 & 2 but are included in s-block?

Answer 12

Hydrogen and Helium.

Question 13

What is the shape and movement of electrons in s-orbitals?

Answer 13

They are spherical and the 2 electrons can move anywhere within the sphere.

Question 14

What is the shape and movement of electrons in p-orbitals?

Answer 14

Dumbbells. Two electrons can move freely within each p-orbital.

Question 15

What are the three types of p-orbitals and how are they distinguished?

Answer 15

Px orbitals lie on the x-axis.
Py orbitals like on the y-axis.
Pz orbitals lie diagonally between the x and y-axis.

Question 16

How is electron configuration written?

Answer 16

The first number is the shell. The second part is the type of orbital. The third part tells you the number of electrons. E.g. 2p4 is in shell 2. It is a p-orbital. And it has 4 electrons.

Question 17

What is ‘spin pairing’ or ‘spin pair repulsion’?

Answer 17

When two electrons occupy one orbital they spin in opposite directions. This is represented by single headed arrows pointing different directions. (one up, one down).

Question 18

What are the two rules to remember when adding electrons to orbitals?

Answer 18

1. Fill from the lowest energy level up.
2. Fill orbitals singularly first and then pair up.

Question 19

What is the rule to remember when removing electrons from orbitals?

Answer 19

Remove from the highest energy level first.

Question 20

How is the electronic configuration of chromium and copper different from normal?

Answer 20

The take an electron from the 4s sub-shell and add it to their 3d sub-shell to create a more stable atom.

Question 21

What is the definition of ionisation energy?

Answer 21

The minimum amount of energy required to remove 1 mole of electrons from 1 mole of atoms in the gaseous state.

Question 22

How does shielding affect ionisation energy?

Answer 22

The more electron shells between the positive nucleus and negative electron that is being removed the less energy is required. There is a weaker attraction.

Question 23

How does nuclear charge affect ionisation energy?

Answer 23

The more protons in the nucleus the bigger the attraction between the nucleus and outer electrons. This means more energy is required to remove the electron.

Question 24

How does atomic size affect ionisation energy?

Answer 24

The bigger the atom, the further away from the nucleus the outer electrons are. The attractive force between the nucleus and the outer electrons reduces so it is easier to remove electrons.

Question 25

Is ionisation endothermic or exothermic?

Answer 25

Endothermic.

Question 26

How does the first ionisation energy change going down a group?

Answer 26

It decreases.

Question 27

Why does the first ionisation energy decrease going down a group?

Answer 27

Increased number of shells.
Increased atomic radii.

Question 28

What is successive ionisation?

Answer 28

The removal of more than 1 electron from the same atom.

Question 29

Where would there be jumps in energy in successive ionisation?

Answer 29

When the electrons are removed from a shell closer to the nucleus.

Question 30

How are elements in the periodic table ordered?

Answer 30

Proton number.

Question 31

What happens to atomic radii across a period?

Answer 31

It decreases.

Question 32

Why does atomic radii decrease across a period?

Answer 32

An increasing charge due to increasing number of protons which pulls the outer shell electrons closer in towards the nucleus.

Question 33

What happens to atomic radii down a group?

Answer 33

It increases.

Question 34

Why does atomic radii increase down a group?

Answer 34

Increasing number of shells.

Question 35

How does ionisation energy change across a period?

Answer 35

It increases.

Question 36

Why does ionisation energy increase across a period?

Answer 36

Increasing nuclear attraction due to increasing number of protons. Shielding is similar across the period so more energy is required to remove an outer shell electron.

Question 37

Why do Aluminium and Boron decrease in first ionisation energy across their periods?

Answer 37

Their outermost electron is being removed from a different sub-shell that is higher in energy.

Question 38

What happens to the first ionisation energy at Sulfur and Oxygen?

Answer 38

There is a slight decrease because of electron repulsion which makes it easier to remove their first electron

Question 39

How does electron repulsion affect ionisation energy?

Answer 39

Less energy is needed to remove an electron from an orbital with two electrons than an orbital with one electron.