Atomic Structure

Question 1

Atomic structure of an atom (3)

Answer 1

Mostly empty space
Very dense Nucleus made of protons and neutrneutrons
Electrons in energy shells

Question 2

Mass of electron

Answer 2

1/1840

Question 3

Proton number

Answer 3

Number of protons in the nucleus of an atom

Question 4

Behaviour of subatomic particles in an electric field

Answer 4

Protons deflected to negative
Electrons deflected (more because they’re lighter) to positive

Question 5

Atomic radius

Answer 5

Half the distance between the nuclei of 2 covalently bonded atoms (just measuring 1 will give you a different reading)
-only for neutral atoms
-cannot determine atomic radius of noble gases
-measured in nanometres x10^-9

Question 6

Trends in atomic radius down a group

Answer 6

Atomic radius increases due to an increase in the number of energy shells and the shielding effect

Question 7

Trends in atomic radius across the period (2)

Answer 7

-Atomic radius decreases across a period due to an increase in the number of protons resulting in a greater nuclear attraction between the electrons and the nucleus
-All atoms in the same period experience similar shielding

Question 8

Ionic radius rule

Answer 8

The more positive the ion the smaller the atomic radius
The more negative the ion the larger the ionic radius

Question 9

Graph to show the trend in ionic radius of successive elements in a period

Answer 9

Question 10

Isotopes

Answer 10

Atoms having the same number of protons but a different number of neutrons
-have the same reactivity as they have the same no. Of valence electrons
-physical properties like mass + density change due to neutron no. Change

Question 11

Relative isotopic mass

Answer 11

Relative mass of a single isotope compared with an isotope of carbon-12 which is assigned a relative mass of 12

Question 12

Important rounding rules for Relative Atomic Mass and isotopic mass

Answer 12

RAM : 1dp
Isotopic mass : always a whole number

Question 13

Rules for orbital diagrams (2)

Answer 13

Pauli’s exclusion principle - each orbital may contain a maximum of 2 electrons spinning oppositely
Hound’s rule - orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron

Question 14

Free radical

Answer 14

Species with 1 or more unpaired electron

Question 15

Ionisation energy

Answer 15

Energy required to remove the outermost electron from each atom in one mole of gaseous atoms to form one mole of gaseous ions with a charge of +1

Question 16

Trends/factors that affect ionisation energy (3)

Answer 16

Distance from nucleus + shielding
Nuclear charge
Spin-pair repulsion

Question 17

How distance from nucleus + shielding affects IE

Answer 17

As you move down a group, valence electrons are further from the nucleus and experience more shielding, reducing the force of nuclear attraction resulting in a lower ionisation energy

Question 18

group with the highest ionisation energy

Answer 18

Group 8

Question 19

How nuclear charge affects IE

Answer 19

Proton number increases as you move across a period, resulting in an increase in nuclear charge and a stronger nuclear attraction. ?The elements experience similar shielding, resulting in an increase in ionisation energy?

Question 20

How spin-pair repulsion affects IE

Answer 20

Spin pair repulsion results in a lower ionisation energy as the paired electrons repel each other

Question 21

Describe electron configuration

Answer 21

Electrons occupy orbitals that are found within energy shells

Question 22

How are energy shells named

Answer 22

By quantum number (starting closest to the nucleus (1))

Question 23

Orbitals

Answer 23

Areas within energy shells where electrons are found
S, p, d and f

Question 24

Sub-shell

Answer 24

one or more orbitals in the same shell which have the same energy levels

Question 25

Orbital rule

Answer 25

Each orbital can only hold 2 electrons

Question 26

S-orbital

Answer 26

Only 1
Spherical in shape
Holds 2 total electrons

Question 27

P-orbitals

Answer 27

3 - x y and z (each hold 2)
6 total electrons in P-subshell
Dumbbell shaped

Question 28

D-orbitals

Answer 28

5 d-orbitals in d-subshell
Holds 10 electrons in total

Question 29

Full electron configuration
Rules (2)

Answer 29

Big numbers never change
Fill 4s before 3d (3d has higher energy) and 5s before 4d

Question 30

Why are there electron configuration exceptions

Answer 30

A half filled or full d-orbital is more stable than a partially filled one. (Stability is the goal)

Question 31

Electron configuration exceptions (2)

Answer 31

Question 32

Describe formation of ions (removing electrons)

Answer 32

The electrons are always removed from the shell furthest from the nucleus

Question 33

How are energy levels numbered

Answer 33

According to their distance from the nucleus (lowest energy, n=1, closest to the nucleus

Question 34

General ionisation energy equation

Answer 34

Question 35

Representing electron configuration diagram (Aufbau)
+ rule

Answer 35

Always put one electron in each p orbital before pairing them

Question 36

What type of reaction is ionisation energy

Answer 36

Endothermic