How long can phosphorescent light last after exposure to UV light?

Phosphorescent light is the result of a process where materials absorb energy from a light source, such as ultraviolet (UV) light, and then release that energy slowly over time. This happens through a mechanism called "forbidden energy states," which allows the absorbed energy to be emitted as light at a later time rather than immediately.

When materials are exposed to UV light, they can store this energy. The duration for which they continue to glow in the dark after the light source is removed varies significantly. Many phosphorescent materials are designed to store energy efficiently and then slowly release it, making it common for them to emit light continuously for several minutes to a few hours, as noted in the correct answer. This duration allows the phosphorescent materials to be practical in various applications, such as glow-in-the-dark products and safety signs.

In contrast, the other options do not accurately reflect the properties of phosphorescent materials. For instance, suggesting that the light only lasts for the duration of UV exposure or for just a few seconds overlooks the nature of phosphorescence, which relies on the slow release of energy, thereby leading to longer-lasting light emission.