Atomic Structure and the Periodic Table | Edexcel A-Level Chemistry (9CH0)
Atomic Structure and the Periodic Table
- 68 questions
- 5 subtopics
- Paper 1: advanced inorganic and physical chemistry
- Paper 1 and Paper 3
Covers the three sub-atomic particles and isotopes, how a mass spectrometer gives relative atomic mass, the ionisation energy evidence for shells and sub-shells, orbitals and electron configuration, and the trends that run across a period and down a group..
It covers protons, neutrons, electrons and isotopes, relative atomic mass and the mass spectrum, ionisation energy and the evidence for sub-shells, orbitals and electron configuration and periodicity across a period and down a group.
Sample questions from Atomic Structure and the Periodic Table
Answer each one closed book first, then open the answer.
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Protons, neutrons, electrons and isotopes
What is meant by the mass number of an atom?
Show the answer
The total number of protons and neutrons in the nucleus of an atom -
Protons, neutrons, electrons and isotopes
How is the number of electrons in a negative ion calculated?
Show the answer
Number of electrons = number of protons plus the magnitude of the charge -
Relative atomic mass and the mass spectrum
Why does the mass spectrum of a diatomic element show multiple peaks?
Show the answer
Because peaks correspond to all possible combinations of isotopes in the molecule -
Relative atomic mass and the mass spectrum
Which isotope combination is responsible for the m/z 74 peak in the mass spectrum of chlorine gas?
Show the answer
³⁷Cl–³⁷Cl -
Ionisation energy and the evidence for sub-shells
How does electron shielding affect ionisation energy?
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Greater electron shielding from inner shells reduces the effective nuclear charge felt by outer electrons, decreasing ionisation energy -
Ionisation energy and the evidence for sub-shells
What evidence do atomic emission spectra provide about electron energy levels?
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Discrete lines in emission spectra show that electrons exist in quantised energy levels (shells) -
Orbitals and electron configuration
What shape does a p-orbital have?
Show the answer
Dumbbell (figure-of-eight) shape -
Orbitals and electron configuration
Which subshell fills first: 4s or 3d?
Show the answer
The 4s subshell fills before the 3d subshell
The 5 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Protons, neutrons, electrons and isotopes | Recall questions on the relative masses and charges of protons, neutrons and electrons, on atomic and mass number, and on what makes two atoms isotopes. | 18 |
| Relative atomic mass and the mass spectrum | Calculating relative atomic mass from isotopic masses and abundances, why the mass spectrum of a diatomic element shows several peaks, the isotope combinations behind the Cl₂ peaks at m/z 70, 72 and 74, the p² : 2pq : q² ratio of peak heights, and what the molecular ion peak shows. | 8 |
| Ionisation energy and the evidence for sub-shells | Recall questions on the definition of first ionisation energy, the trends across a period and down a group, and how successive ionisation energies reveal shells and sub-shells. | 11 |
| Orbitals and electron configuration | Recall questions on s, p and d orbitals, the order in which sub-shells fill, spin pairing, and writing configurations for atoms and for ions. | 20 |
| Periodicity across a period and down a group | What periodicity means, how structure and bonding set the melting and boiling temperatures across periods 2 and 3, the rise in first ionisation energy across a period and its falls between groups 2 and 3 and groups 5 and 6, atomic radii across a period and down a group, and using logarithms, hand-held spectroscopes and weighted means with periodic data. | 11 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
Edexcel A-Level Chemistry Active Recall Guide
Every topic, not just this one. 1,534 questions with their answers.