Atomic Structure and the Periodic Table

What Atomic Structure and the Periodic Table covers

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.

The 5 subtopics

Each one has its own page.

• Protons, neutrons, electrons and isotopesRecall questions on the relative masses and charges of protons, neutrons and electrons, on atomic and mass number, and on what makes two atoms isotopes.Open →
• Relative atomic mass and the mass spectrumCalculating 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.Open →
• Ionisation energy and the evidence for sub-shellsRecall 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.Open →
• Orbitals and electron configurationRecall questions on s, p and d orbitals, the order in which sub-shells fill, spin pairing, and writing configurations for atoms and for ions.Open →
• Periodicity across a period and down a groupWhat 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.Open →

What you need to know

Answer each one before you reveal it.

Take Atomic Structure and the Periodic Table further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Atomic number vs Mass number

  Atomic number: number of protons in a nucleus. Mass number: total number of protons and neutrons in a nucleus.

• Isotope vs Ion

  Isotope: atom with fixed proton count and differing neutron count. Ion: charged species formed by electron loss or gain.

• Orbital vs Shell

  Orbital: region able to hold up to two opposite-spin electrons. Shell: collection of orbitals sharing a principal energy level.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What two types of particle are found in the nucleus of an atom?

   Model answer

   Protons and neutrons

2. 2

   Where are electrons located within an atom?

   Model answer

   In shells (energy levels) surrounding the nucleus

3. 3

   Give a proton's relative charge and relative mass.

   Model answer

   Relative mass = 1, relative charge = +1

4. 4

   Give a neutron's relative charge and relative mass.

   Model answer

   Relative mass = 1, relative charge = 0

5. 5

   Give an electron's relative charge and relative mass.

   Model answer

   Relative mass = 1/1836 (approximately 0.0005 or negligible), relative charge = −1

6. 6

   Define atomic number.

   Model answer

   The number of protons in the nucleus of an atom

What is inside Levo

Six ways to work the same material.

Atomic Structure and the Periodic Table revision questions

What does Atomic Structure and the Periodic Table cover in Edexcel A-Level Chemistry?

5 subtopics: 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. Each one has its own page with questions and model answers.

How is Atomic Structure and the Periodic Table organised?

By the Edexcel 9CH0 specification, subtopic by subtopic, so it matches the order you are taught it in.