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Edexcel A Level Chemistry (9CH0)

Mass Spectrometry

Mass spectrometry separates positive ions according to their mass-to-charge ratio, written as m/z. These pages build from the operation of the mass spectrometer through to isotope abundance, relative atomic mass and interpreting molecular spectra.

Exam Paper
Paper 1
9CH0/01 – Advanced Inorganic and Physical Chemistry
Specification Points
6 – 9
3 points covered
Sub-topics
3 lessons
Revision notes available
Exam Board
Edexcel
Pearson 9CH0

Revision Notes

3 revision notes, in the order the specification teaches them.

A mass spectrometer with a stream of ions curving to a detector
1

The Mass Spectrometer

Revise vaporisation, ionisation, acceleration, deflection, detection and why ions are separated by m/z.

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A three-peak isotope spectrum beside a balance
2

RAM Calculations

Use isotopic mass and percentage abundance data to calculate relative atomic mass using weighted means.

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Three diatomic molecules and their three spectrum peaks
3

Predicting Diatomic Mass Spectra

Predict molecular ion peak patterns for diatomic molecules using isotope combinations and probability ratios.

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Summary Map

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Summary map

Download, print and revise the key facts of this topic at a glance.

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Summary map · PDF

Atoms and Mass Spectrometry Map

Edexcel A Level Chemistry · Topic 1 Atomic Structure · Atoms and Mass Spectrometry

The whole section on one A4 page: sub-atomic particles, isotopes, the mass spectrometer, relative isotopic, atomic and formula masses, and the spectra of molecules.

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Topic 1 Atomic Structure and The Periodic Table taught by a specialist chemistry teacher, in 5 recorded video lessons that follow the specification.

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8 exam-style multiple-choice papers, MCQ (A) to (H): 155 questions on Topic 1 Atomic Structure and The Periodic Table, written the way the exam asks them.

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Specification

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1.1

  1. a

    know the structure of an atom in terms of electrons

    Revise
  2. b

    know the structure of an atom in terms of protons

    Revise
  3. c

    know the structure of an atom in terms of neutrons

    Revise

1.2

  1. a

    know the relative mass of protons

    Revise
  2. b

    know the relative charge of protons

    Revise
  3. c

    know the relative mass of neutrons

    Revise
  4. d

    know the relative charge of neutrons

    Revise
  5. e

    know the relative mass of electrons

    Revise
  6. f

    know the relative charge of electrons

    Revise

1.3

  1. a

    know what is meant by the term 'atomic (proton) number'

    Revise
  2. b

    know what is meant by the term 'mass number'

    Revise

1.4

  1. a

    be able to determine the number of electrons in an atom from atomic number, mass number and charge

    Revise
  2. b

    be able to determine the number of protons in an atom from atomic number and mass number

    Revise
  3. c

    be able to determine the number of neutrons in an atom from atomic number and mass number

    Revise
  4. d

    be able to determine the number of electrons in an ion from atomic number, mass number and charge

    Revise
  5. e

    be able to determine the number of protons in an ion from atomic number and mass number

    Revise
  6. f

    be able to determine the number of neutrons in an ion from atomic number and mass number

    Revise

1.5

  1. 1.5

    understand the term ‘isotopes’

    Revise

1.6

  1. a

    be able to define the term 'relative isotopic mass' based on the 12C scale

    Revise
  2. b

    be able to define the term 'relative atomic mass' based on the 12C scale

    Revise

1.7

  1. a

    understand the term 'relative molecular mass'

    Revise
  2. b

    understand the term 'relative formula mass'

    Revise
  3. c

    calculate relative molecular mass from relative atomic masses

    Revise
  4. d

    calculate relative formula mass from relative atomic masses

    Revise
  5. e

    know that definitions of relative molecular mass and relative formula mass will not be expected

    Revise
  6. f

    know that the term 'relative formula mass' should be used for compounds with giant structures

    Revise

1.8

  1. a

    be able to analyse mass spectrometry data to calculate relative atomic mass from relative abundance of isotopes

    Revise
  2. b

    be able to interpret mass spectrometry data to calculate relative atomic mass from relative abundance of isotopes

    Revise
  3. c

    be able to calculate relative abundance of isotopes from relative atomic mass and mass spectrometry data

    Revise

1.9

  1. a

    be able to predict mass spectra for diatomic molecules, including chlorine, given isotopic abundances

    Revise
  2. b

    be able to predict relative peak heights for diatomic molecules, including chlorine, given isotopic abundances

    Revise

1.10

  1. a

    understand how mass spectrometry can be used to determine the relative molecular mass of a molecule

    Revise
  2. b

    know that this is limited to the m/z value for the molecular ion, M+, giving the relative molecular mass of the molecule

    Revise

1.11

  1. a

    be able to define the term 'first ionisation energy'

    Revise
  2. b

    be able to define the term 'successive ionisation energies'

    Revise

1.12

  1. a

    understand how ionisation energies are influenced by the number of protons

    Revise
  2. b

    understand how ionisation energies are influenced by electron shielding

    Revise
  3. c

    understand how ionisation energies are influenced by the electron sub-shell from which the electron is removed

    Revise

1.13

  1. 1.13

    understand reasons for the general increase in first ionisation energy across a period

    Revise

1.14

  1. 1.14

    understand reasons for the decrease in first ionisation energy down a group

    Revise

1.15

  1. i

    understand how ideas about electronic configuration developed from: the fact that atomic emission spectra provide evidence for the existence of quantum shells

  2. ii

    understand how ideas about electronic configuration developed from: the fact that successive ionisation energies provide evidence for the existence of quantum shells and the group to which the element belongs

    Revise
  3. iii

    understand how ideas about electronic configuration developed from: the fact that the first ionisation energy of successive elements provides evidence for electron sub-shells

    Revise

1.16

  1. a

    know the number of electrons that can fill the first quantum shell

    Revise
  2. b

    know the number of electrons that can fill the second quantum shell

    Revise
  3. c

    know the number of electrons that can fill the third quantum shell

    Revise
  4. d

    know the number of electrons that can fill the fourth quantum shell

    Revise

1.17

  1. 1.17

    know that an orbital is a region within an atom that can hold up to two electrons with opposite spins

    Revise

1.18

  1. a

    know the shape of an s-orbital

    Revise
  2. b

    know the shape of a p-orbital

    Revise

1.19

  1. a

    know the number of electrons that occupy s subshells

    Revise
  2. b

    know the number of electrons that occupy p subshells

    Revise
  3. c

    know the number of electrons that occupy d subshells

    Revise

1.20

  1. a

    know that electrons fill subshells singly before pairing up

    Revise
  2. b

    know that two electrons in the same orbital must have opposite spins

    Revise

1.21

  1. i

    be able to predict the electronic configurations, using 1s notation and electrons-in-boxes notation, of: atoms, given the atomic number, Z, up to Z = 36

    Revise
  2. ii

    be able to predict the electronic configurations, using 1s notation and electrons-in-boxes notation, of: ions, given the atomic number, Z, and the ionic charge, for s and p block ions only, up to Z = 36

    Revise

1.22

  1. 1.22

    know that elements can be classified as s, p and d-block elements

1.23

  1. 1.23

    understand that electronic configuration determines the chemical properties of an element

    Revise

1.24

  1. 1.24

    understand periodicity in terms of a repeating pattern across different periods

    Revise

1.25

  1. i a

    understand reasons for trends in melting temperatures of elements from periods 2 and 3 based on given data in terms of structure and bonding

    Revise
  2. i b

    understand reasons for trends in boiling temperatures of elements from periods 2 and 3 based on given data in terms of structure and bonding

    Revise
  3. ii a

    understand reasons for trends in ionisation energy of elements from periods 2 and 3 based on given data

    Revise
  4. ii b

    understand reasons for trends in ionisation energy of elements from periods 2 and 3 based on recall of plots of ionisation energy versus atomic number

    Revise

1.26

  1. a

    be able to illustrate periodicity using electronic configuration data

    Revise
  2. b

    be able to illustrate periodicity using atomic radii data

    Revise
  3. c

    be able to illustrate periodicity using melting temperature data

    Revise
  4. d

    be able to illustrate periodicity using boiling temperature data

    Revise
  5. e

    be able to illustrate periodicity using first ionisation energy data

    Revise