3.1.1 Atomic Structure

Question 1

What is ionisation energy?

Answer 1

The energy required to remove one mole of electrons from one mole of a compound to produce one moles of 1+ positive ions all in the gaseous state

Question 2

Write the first ionisation equation for Magnesium including state symbols

Answer 2

Mg(g) -> Mg+(g) + e-

Question 3

Write the third ionisation energy equation for argon including state symbols

Answer 3

Ar2+(g) -> Ar3+(g) + e-

Question 4

What is the three main factors affecting ionisation energy?

Answer 4

Distance from nucleus - smaller atoms have higher attraction between + nucleus and - electrons
Nuclear charge - Higher positively charges nucleus means stronger attraction to electrons
Shielding between nucleus and outmost electron - Repulsion by electrons in inner shells decreases ionisation energy

Question 6

Does ionisation energy decrease or increase down a group and why?

Answer 6

IE decreases
Bigger atoms, more shielding so weaker attraction from nucleus to outmost electron in outer shells.
(Outweighs the increase in protons)

Question 7

Across a period where is the evidence for sub-levels?

Answer 7

General increase due to increasing proteins and no increase in shielding. However there will be spotted drops in IE due to sub shells

Question 8

How does ionisation energy change across a period?

Answer 8

Increase ionisation energy as the proton number gets larger which makes the atoms smaller. Due to the same level of shielding their is stronger attraction between nucleus and outmost electron

Question 9

What are sub shells?

Answer 9

A subdivision of electron shells separated by electron orbitals

Question 10

List the subshells

Answer 10

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6

Question 11

What does each principle energy level have?

Answer 11

1 - 1s
2 - 2s, 2p
3 - 3s, 3p, 3d
4 - 4s, 4p, 4d, 4f

Question 12

How many electrons in the principle energy level 3?

Answer 12

18

Question 13

State Hund’s rule

Answer 13

Electrons prefer to occupy orbitals on their
own, and only pair up when no empty orbitals
of the same energy are available.

Question 14

Uses of mass spectrometry

Answer 14

Identify unknown compounds
Determine the abundance of each isotope in an element
Gain information about structure and chemical properties of molecules

Question 15

Different stages TOF calculations

Answer 15

Ionisation, acceleration, flight tube, detection