UV Absorption
UV Absorption is what happens when a material soaks up ultraviolet light instead of letting it pass through.
Think of it this way
Hold a piece of dark sunglasses glass between a flashlight and the wall. The shadow is darker because the lens absorbed some of the light. Sunscreen works the same way for UV rays you cannot see — it soaks up the invisible light before it can reach your skin.
Explaining uv absorption by grade level
Think about putting sunscreen on your skin before going outside. The sun sends invisible rays you cannot see. Sunscreen works like a shield. It soaks up those invisible rays so they never reach your skin. Thicker sunscreen soaks up more of the rays. That is how sunscreen keeps you from getting a sunburn.