Two presenters use animations to show how protons, neutrons and electrons make up atoms. They explain the relative masses, sizes, locations and charges of these subatomic particles.

First broadcast:
21 November 2008

Introduce students to the three subatomic particles, each with a specific charge, mass and position within the atom. As they watch the clip, students should note down the differences between protons, neutrons and electrons.
Consolidate understanding of the link between the number of protons and the atomic number, between protons and neutrons and the mass number and the balance of protons and electrons that results in atoms being neutral.
Students could use beads, sweets, balls or themselves to build models of the positions of particles in the atoms of different elements.