(female describer) Title: "Bite Sci-zed Science" Sci-zed is spelled S-c-i hyphen z-e-d. Before I begin this video, I want to note that the title is not "Fun With Matches" or "Playing With Fire," because matches are not a toy. But they are a tool. And I believe if you're going to use a tool, you should understand the science behind it. And I know that you guys are too smart for me to have to make this announcement. But I do just have to say-- please, do not play with matches or any other kind of fire for that matter. With that out of the way, let's get onto the science. So why do we find matches and fire to be so intriguing? At least for me, I think it comes from the fact that I take two things which are both cold and dark, and when I strike them together I create both light and heat. And there's something about that process that has an almost magical, intangible quality to it. So why does it happen? First, let's look at the anatomy of the objects in question. First, we have our matchstick. Now, the match head has three important components-- sulfur, an oxidizing agent, potassium chlorate, and powdered glass. Next we have our striking surface. This contains sand, some more glass, and red phosphorus. When you strike the match quickly against the surface, the friction between the two, enhanced by that glass and sand, causes a little bit of the red phosphorus to turn into white phosphorus vapor. This spontaneously ignites. And its heat decomposes the oxidizing agent, potassium chlorate, liberating oxygen, which helps to keep the flame going. At this point, the sulfur starts to burn, which ignites the wood of the match. I should note that this isn't just any old chunk of wood either. Matchsticks are often made from aspen, which is both strong and flexible enough for the job. They've been infused with ammonium phosphate which helps to prevent smoldering after you blow out the flame. They've also been dipped in paraffin wax which helps the flame to travel evenly down the matchstick. Now, these are safety matches, but they're also strike anywhere matches. Which are the same principle, they just have the red phosphorus in the match head as well. It's everything all packed into one piece so you can strike it against any hard surface. Now, after you light a match, there's a very distinctive smell. And that smell, a little bit like rotten eggs, is sulfur dioxide. And it's produced when the sulfur and the oxygen combine and burn. And we can write the chemical equation for this as sulfur plus oxygen yields sulfur dioxide. An everyday tool that I bet you didn't know the science behind. Go forth. Do science.