Phosphorescence occurs when energy is stored and released...

• A. Gives off light immediately when exposed.
• B. Gives off light after absorbing energy stored for a while.
• C. Gives off light only when heated.
• D. Never emits light.

Answer: (B)

Phosphorescence happens when a material absorbs energy and stores it in long-lived excited states, then releases that energy as light slowly after the light source is removed. The glow can continue for a short time or even minutes to hours as trapped electrons gradually recombine and emit photons. This is why glow-in-the-dark materials shine after you’ve turned off the lights. It’s different from fluorescence, which stops almost immediately when the excitation stops, and it isn’t caused by heating (that would be a different phenomenon). So the idea of energy being stored and then released as light over time best describes phosphorescence.