So imagine there's a little thing called tetrapropylammonium perruthenate. It's really hard to say, so we can call it TPA for short.
Now, TPA is made up of four little propyl groups joined together, and they're all stuck to a special rhenium atom. This rhenium atom is super strong and holds everything together in a special way.
TPA is really good at doing something called "oxidizing." That's just a fancy word for making things react with oxygen in a special way.
Scientists like to use TPA to make new chemicals, because it's really good at making certain kinds of reactions happen. It's like a magic potion that makes things change into something else.
But even though TPA is super cool, it can be dangerous if you touch it or breathe it in. So just like with any other chemical, you should always let a grown-up scientist handle it.