The Gallium Beating Heart
Induced by the touch of an iron nail, gallium metal appears to take on a life of its own as it continuously oscillates between a dull flat puddle and a shiny sphere.
Electrons from a corroding anode (iron nail) are transferred to Ga3+, forming gallium metal. The gallium metal is spherical in shape due to its surface tension. Dichromate oxides the surface of the gallium, creating Ga3+ and breaking the surface tension in the gallium metal. This oscillation continues for about 30 minutes as the dichromate concentration gradually decreases.