In this topic, we will learn about atomic structure, starting with the idea that atoms are mostly empty space surrounding a small, dense nucleus containing protons and neutrons, with electrons arranged in shells around the nucleus. We will describe the properties of sub-atomic particles, use atomic and mass numbers to determine the composition of atoms and ions, and explain trends in atomic and ionic radius across the Periodic Table.

Next, we will study isotopes, learning how they are defined and represented, and explaining why isotopes of the same element have the same chemical properties but different physical properties.

We will then develop an understanding of electronic structure by exploring shells, sub-shells and orbitals, the arrangement and energies of electrons, and how electronic configurations are written and explained. Orbital shapes, electrons-in-boxes notation and free radicals will also be introduced.

Finally, we will examine ionisation energy, defining first and successive ionisation energies, explaining their trends and variations, and using ionisation energy data to deduce electronic configurations and an element’s position in the Periodic Table.