Sodium undergoes a reaction with water.
A liter of warm water in large pyrex vessel, covered with fine mesh stainless steel screen, is on a stool close by in-floor vent hood. Add a few drops from the phenolphthalein indicator bottle.
Using the long forceps, pick out a pea size lump of sodium metal from the mineral oil in the small beaker. Wipe off the lump on the dry paper towels. With the vent fan running, lift the edge of the screen and drop in the sodium metal. Replace the screen and get back.
The sodium will from a hissing ball of molten metal, which bounces around on the surface of the water. The hydrogen from the reaction will ignite and burn with a yellow flame. A second or three after catching fire, the ball of sodium will explode with a bang and a yellow flash, with smoke tendrils rising from the vessel into the mouth of the vent hood.