<human>:  How can I explain the concept of ultraviolet radiation to a 10 year old?
<bot>: Ultraviolet radiation is a kind of invisible light that comes from the sun. It is powerful enough to damage our skin, but it can also be beneficial. Sun exposure to UV radiation helps our bodies produce vitamin D, which is important for healthy bones and teeth. Sunscreen helps protect us from UV radiation by blocking some of the harmful effects while still letting the good rays through. For kids, it's important to remember to wear sunscreen when they are out playing in the sun, even on cloudy days.