We are looking forward to taking our son this year for the first time.ĭo you find yourself thinking about the show from a chemist’s perspective?Ī lot of chemists, I think especially inorganic chemists, have an attraction to fire, so I really enjoy the show, but I also appreciate the chemistry when I’m watching them. We don’t have a particular site that we go to yet we’re still feeling it out. Now my husband and I typically will go and watch them here, along the river for example, or just from a high vantage point. Then there would be a big neighborhood demonstration for all the kids in the neighborhood. That was a big deal when I was a kid, to have someone go and get fireworks that were much more intense. I grew up in Michigan, and we always had someone in the neighborhood who would drive out of state at some point before the 4th of July. What were your 4th of July traditions growing up? Do you have a favorite place to watch fireworks here in Philadelphia? The firework is primarily a combination of compounds to provide the explosion, and the metal salts are additives that give you different colors.
The salts are easy to disperse, and they’re less reactive when they are going into the firework. That combination of factors gives rise to specific sets of characteristics for a given metal.Īs we traverse the periodic table, elements get heavier, and that will also contribute to the relative energy levels that are associated with the distribution of electrons, which will also change the color at which these elements emit light. It’s the arrangement of electrons in shells outside of the metal’s nucleus that allows for the absorption of energy and the emission of different wavelengths (colors) of light.Įach element brings along a specific ‘flavor’ based on their number of electrons, and the electrons have interactions between each other in the shells around the nucleus. Why do different metals burn in different colors? You want the firework to go off at an appointed time, so by using the binder you can engineer the explosion and timing together with other explosions in the show. The binder just holds everything together and, ideally, makes the mixture stable so that it doesn’t go off unexpectedly.
You just need a spark under that situation to get the reaction moving to convert all of that fuel, and oxidizer, into the products. So you’re creating a mixture of the fuel and the oxidizer, and that’s a lot of stored potential energy that’s ready to be released. The oxidizer is receiving the electrons upon reaction with the oxidizer, energy is released, and the electrons are transferred from one to the other. A chemical reaction, typically combustion, is occurring through reaction of the fuel with an oxidizer. The fuel is a source of electrons, something that stores energy, and it will be burned in the course of the explosion. In any kind of explosive, rocket engine, or energetic material that you’re trying to develop to explode or propel something, you need a combination of a fuel and an oxidizer. You could have a relatively slow chemical reaction, like the Pharaoh’s serpent or ‘black snake’ firework, but if you want an explosion then you need the reaction to occur quickly to produce a lot of gas in a short amount of time.Ī standard firework has a fuel, oxidizer, and binder. What’s the difference between an explosive firework display and other combustion reactions, like burning wood?įor an explosion, the goal is to generate as much gaseous product in as short of a time as possible. The metal salts heat up to become ‘excited’ in that highly energetic situation and emit light as a result.
The explosion spreads out all that material, which is in a super-heated state, and there’s different metal salts that are added to create the colors.
Those three reagents react to make solid potassium carbonate, solid potassium sulfate, nitrogen gas, and carbon dioxide gas, so you have solid reagents reacting to make gases. You’re doing a combustion reaction out of those types of materials that creates this detonation explosion. Traditionally, three reagents, potassium nitrate, carbon, and sulfur, make gunpowder. What can you tell us about the chemical reactions that go into a fireworks display?