By Nikhita Shankar
What do your toothpaste and a supernova a gazillion miles away have in common? Fluorine.
Fluorine is a rare chemical element sandwiched between oxygen and neon on the periodic table and has two isotopes. It is what we call a gaseous halogen. In contrast to oxygen and neon, fluorine does not make the top 20 list of the universe’s elements. Fluorine is an element that stars rarely create during their lifetimes while neon and oxygen are created in bigger amounts by stars. Fluorine is unique, for it is the most chemically reactive element element. This means it is extremely likely to bond with other elements. It is also the most electronegative element in the periodic table (1)!
Some uses of fluorine include refrigerators and rocket fuel. Your refrigerator works using a set of tubes that move through your refrigerator, and fluorine is the main element that is contained in these tubes. So you can thank Fluorine for that vanilla ice cream you ate yesterday! Rocket fuel requires highly explosive elements, and fluorine is a highly explosive element because it is highly reactive (in fact, the most reactive), so it is used in rocket fuel. In other terms, it has a high specific impulse value. What does that mean? It means that if fluorine is used a smaller amount of fuel can be used to move a rocket at high speeds (2).
If fluorine gas is inhaled by a human being, that person will die, but fluorine does serve an important purpose in our everyday lives. It is in many of the foods that we eat and tea, but most importantly it is in our toothpaste! Fluorine is present in toothpaste, as you may have noticed. It is the part of toothpaste that does the job, reducing the buildup of plaque on our teeth and strengthening our teeth. However, toothpaste only contains a small amount of Fluorine (3).
You may not have noticed that fluorine is produced when the center of a star collapses. Fluorine is produced by the humongous stars because when they explode the star lets go of 10^58 highly energetic neutrinos, for the electrons and the protons are crushed together to form neutrinos during the explosion. When such a massive star dies, it releases fluorine into the universe. This is because these neutrinos are like children that have had too much sugar, bumping into a few neutrons and protons here and there in the nuclei of the star which are enough to produce fluorine. Without these neutrinos, their energy would not be accessible to create Fluorine (4).
What is a neutrino? To start of it is an “elementary” particle, a particle that does not consist of any other particles. Other elementary particles include leptons and quarks. Neutrinos rarely reacts with “normal” matter, for there are a huge number of them moving through our bodies at this very second. Strangely enough, they are particles that can move through the entire earth without being affected, for they do not like to interact with other particles (5). Neutrinos are also unique because they can travel at speeds that are close to the speed of light. It has a mass of almost 0 and have no electric charge. When are these strange particles produced? They are particles are produced for instance when radioactive decay occurs (6) .
Let’s take a step back into the history of our universe, all the way back to the BIG BANG. There is reason to believe that The Big Bang produced the greatest number of neutrinos in the history of neutrinos. Scientists believe this because these special particles have no electric charge and negligible mass. Neutrinos were formed during the Big Bang even before the very first atoms were formed. However, we continue to see stars like our very own Sun producing them today.
But what in the world do these neutrinos and supernovae have to do with fluorine? Scientists at National Optical Astronomy Observatory predict that two thirds of earth’s fluorine is made up of neutrinos from supernovas that exploded! So you can thank supernovas for your clean white teeth.