radioactive

Radioactive refers to materials or things that give off energy in the form of tiny particles, often with potential harm.

When people talk about something being radioactive, they usually mean that it emits these small particles that can hurt us if we're close to them. This is a big concern when talking about nuclear accidents, polluted areas, and certain types of medical treatment. For example, a person who has had radiation therapy for cancer might still have some radioactive material in their body. You might hear people say "This area is off-limits due to high levels of radioactivity" or "Don't touch that old watch because it's highly radioactive." In these cases, the focus is on the potential danger and how we need to be careful around things that give off this kind of energy.