zerostatereflex:

Gallium droplets fusing together in warm sulphuric acid.

And what is happening from an energy standpoint?

“The gallium is trying to minimize its surface area by forming a single
sphere. The sulfuric acid presumably prevents the surface of the
droplets from oxidizing (which would inhibit their ability to coalesce).
Heat is applied in order to keep the droplets liquid since the melting
point of gallium is just above room temperature.”