Final answer:
When glowing occurs as long as phosphors are being stimulated, it is referred to as persistent glow.
Step-by-step explanation:
When glowing occurs as long as phosphors are being stimulated, it is referred to as Persistent glow. Phosphorescence is the de-excitation of a metastable state. Glow-in-the-dark materials, such as luminous dials on some watches and clocks and on children's toys and pajamas, are made of phosphorescent substances. Visible light excites the atoms or molecules to metastable states that decay slowly, releasing the stored excitation energy partially as visible light.