Fluor is a chemical element with the symbol F and atomic number 9. It is a pale yellow gas at room temperature and is known for being the most reactive and electronegative of all elements. Fluor is commonly found in nature as part of various minerals, such as fluorite, and is used in a variety of applications, including toothpaste and non-stick coatings. Due to its high reactivity, fluor can form compounds with almost all other elements, including hydrogen and carbon. One of its most notable compounds is hydrofluoric acid, which is used in industrial processes. However, handling fluor and its compounds requires caution due to their corrosive nature.