Chemical equations Brainpop

Hey. Moby, you should never do that in a lab. You're gonna get me in trouble. Dear Tim and Moby, we're doing chemical equations in school next week. What does that mean? From Wendell. Well, chemical equations are a way to simply represent chemical reactions. Beep. A chemical reaction is when different substances combine to form a new substance, or when one substance breaks up into different substances. When different atoms bond together, new substances are made with totally different properties than the atoms had on their own. For example, oxygen and hydrogen can combine to form water. You've probably heard water called H2O. That's its molecular formula. One molecule of water is two hydrogen atoms bonded with one oxygen atom well, see, every element on the periodic table has its own symbol. Symbols usually start with the first letter of the element they represent, like, O, for oxygen, H for hydrogen, AR for argon, and CS for cesium. Using the symbols from the periodic table, we can represent any substance in the universe with a molecular formula. Hydrochloric acid, the stuff in your stomach that digests food is one hydrogen atom bonded to one chlorine, HCL, the ammonia in this window cleaner is one nitrogen atom combined with three hydrogen atoms NH3. We can use those molecular formulas and chemical equations to show how different substances form. For example, table salt is made of one sodium atom, and one chlorine atom, the chemical equation shows the reactants going through a process to form products. The arrow shows what direction the chemical reaction is taking. Beep. Actually, I sort of lied. It's not that simple. In reality, chlorine naturally occurs in pairs. So a molecule of chlorine is actually written as Cl2. You notice anything about that chemical equation? Well, there's a chlorine atom missing. See, the reactants have two chlorine atoms, and one sodium atom. But the product has only one chlorine atom. Since you can't destroy or create matter, the equation must be wrong. That's where balancing chemical equations, or stoichiometry comes into play. To make the equation work, we need to change some of the numbers. You need two sodium atoms to bond with one chlorine molecule. They react to form two molecules of salt. Now it works. Each side of the equation has two sodiums and two chlorines. This proportion, two sodium atoms for every chlorine molecule, will be the same, no matter how much salt you're making. Beep. Well, unless you know some pretty high level algebra, there's no real method for balancing chemical equations. You just have to use trial and error until the equation balances out. It can take some time. I don't know what that is. Cut that out.