The structure of atoms: 9.2.7 - Electronic configuration and stability
Video evidence of the reactivity of group 1 metals. Videos can be found here
Student follow up
Pages 32-34 in the text to highlight the stability of group 18 (8) elements, the inert gases.
Focus on the terms 'valence shell and valence electrons'.
Short single lesson.
* Teaching Notes: It must be stressed that atoms are not inherently stable. This means that they tend to change into other species by bonding, either to other atoms of the same type or to different types of atoms. The reason for this lies in the electron arrangement.