NaK, the sodium–potassium alloy, displays a fascinating property at room temperature that students really don’t expect.

This is a great demonstration to use when talking about metallic bonding or alloys.

Read the article that accompanies this video in the July 2016 issue of Education in Chemistry at http://rsc.li/EiC416ec

This is part of the Education in Chemistry Exhibition Chemistry series: chemistry demonstrations to capture your students' imaginations: http://rsc.li/EiCExChem

Image credits
1:57
Zinc: By takomabibelot [CC BY 2.0 (http://creativecommons.org/licenses/b...)], via Wikimedia Commons
Copper: By Alchemisthp (psemendelejew.de) (eigene Arbeit (own work)) [FAL or CC BYSA 3.0 de (http://creativecommons.org/licenses/b...)], via Wikimedia Commons
Brass: Skokloster Castle / Fredrik Andersson / CC BYSA [CC BYSA 3.0 (http://creativecommons.org/licenses/b...) or Public domain], via Wikimedia Commons
2:11
By Lothar Neumann, Gernsbach [1] (Karlsruhe:Bild:Philippsburg2.jpg) [CC BYSA 2.5 (http://creativecommons.org/licenses/b...)], via Wikimedia Commons