Nitrogen pentafluoride is a type of gas made up of tiny particles that we can't see. It is made up of five atoms of fluorine and one atom of nitrogen.
This gas is very strong and can react with lots of other things because of its structure - it has five atoms of fluorine surrounding just one atom of nitrogen. This makes it a bit unusual!
Sometimes scientists use nitrogen pentafluoride to clean up things like computer chips that are really tiny and need to be super clean. When the gas is used to clean things, it helps to get rid of any dirt, dust, or other particles that could get in the way of how the computer works.
Even though nitrogen pentafluoride is very useful for cleaning things, it's important to use it carefully because it can be harmful if you breathe it in. That's why scientists who use it always make sure to wear special clothes and masks to stay safe.