Question

2 world use of the ultraviolet waves is Blacklights, emit UVA radiation, which is a type of ultraviolet light that we can't see. Many materials contain special chemicals called phosphors that absorb this invisible UV energy and then release it as visible light, making them appear to glow in the dark. This fluorescent effect is used for entertainment purposes like glow-in-the-dark posters and parties, but also has practical applications. Security features on money, passports, and IDs include special inks that only show up under UV light, making it harder to create fakes. The UV light reveals hidden patterns or text that aren't visible in normal light.​ put it into simpler words

Answer 1

Here’s a much simpler version:

Blacklights give off a type of invisible light called UVA (ultraviolet A). Some materials have chemicals called phosphors that soak up this invisible light and then glow in colors we can see. That’s why things like glow-in-the-dark posters or party decorations light up under blacklights.

This glowing effect is also useful for security. Special inks on money, passports, and ID cards only show up under UV light. That makes hidden patterns or writing appear and helps stop people from making fakes.