Excimer

Excimer is a big fancy word that describes something pretty neat. You know how in school, you learn about atoms and molecules, and how they are made up of tiny little pieces? Well, sometimes these tiny pieces get really excited and start moving around really fast. When this happens, they can join together and form a special type of molecule called an excimer.

Excimers are special because they are really unstable, which means they don't last very long. But while they're around, they can do all sorts of interesting things, like give off light or change the way other molecules behave. Scientists can even use excimers to make lasers, which are cool beams of light that can be used in all sorts of ways, like cutting things or reading information off of CDs and DVDs.

So if you ever hear someone talking about excimers, just remember that they're talking about really fast-moving pieces that like to join together and do all sorts of interesting things.