This clip shows how carbon is made up from sub-atomic particles. Electron shells are mentioned. Two extra neutrons are added to make an unstable isotope which explodes at the end.

First broadcast:
21 November 2008

This clip could be used to illustrate and introduce the concept of isotopes as an extension to the basic knowledge of atomic structure required. Ensure students have an understanding of how mass and atomic numbers can explain the number of protons, neutrons and electrons in atoms. Explain with examples that isotopes have the same number of electrons and protons, it is the number of neutrons that changes.