Question

The_________________ metal melts into a silvery globule and darts about freely on the surface of water.

Answer 1

• When a piece of sodium metal is dropped in cold water it floats on the water surface and melts forming a silvery globule that darts about the surface of water catches fire and burns with a golden-yellow flame.
• $2\mathrm{Na}+2{\mathrm{H}}_2\mathrm{O}\to \underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}}+{\mathrm{H}}_2\uparrow$
• The reaction is violent but comparatively less violent than potassium. Sodium melts into a silvery globule and darts about the water.

Therefore, the sodium metal melts into a silvery globule and darts about freely on the surface of the water.