Fluorine vs Fluoride
The elements in the periodic table are not stable except the noble gases. Therefore, elements try to react with other elements to gain the noble gas electron configuration to achieve the stability. Likewise, fluorine also has to get an electron to achieve the electron configuration of the noble gas, neon. All metals react with fluorine, forming fluorides. Fluorine and fluoride have different physical and chemical properties due to the change of one electron.
Fluorine is an element in the periodic table which is denoted by F. It is a halogen (17th group) in the 2nd period of the periodic table. The atomic number of fluorine is 9, thus, it has nine protons and nine electrons. Its electron configuration is written as 1s2 2s2 2p5. Since the p sub level should have 6 electrons to obtain the Neon, noble gas electron configuration, fluorine has the ability to attract an electron. Fluorine has the highest electronegativity in the periodic table, which is about 4, according to the Pauling scale. The atomic mass of fluorine is 18.9984 amu. Under room temperature, fluorine exists as a diatomic molecule (F2). F2 is a pale yellow – greenish color gas. Fluorine has a melting point of -219 °C and a boiling point of -188 °C. F-17 is not a stable isotope of fluorine and it has half life of 1.8 hours. F-19 is a stable isotope of Fluorine. The abundance of F-19 on earth is 100%. Fluorine can oxidize oxygen and its oxidation state is -1. Fluorine gas is denser than air and it can also be liquefied and solidified. Fluorine is highly reactive, and this may be due to its high electronegativity, also due to the weak fluorine- fluorine bond. The reactions of fluorine with most of the other molecules are fast. Because of the reactivity, fluorine is not found as free element.
Fluoride is the resulted anion, when fluorine abstracts an electron from another electropositive element. Fluoride is represented by the symbol F-. Fluoride is a monovalent ion with -1 charge. Therefore, it has 10 electrons and nine protons. The electron configuration of fluoride is 1s2 2s2 2p6. Fluoride exists in ionic compounds such as sodium fluoride, calcium fluoride (fluorite) and HF. Fluoride also exists naturally in water sources. It is known that, fluoride helps in preventing tooth decay; therefore, it is added to toothpastes.
Fluorine vs Fluoride
– Fluoride is the reduced form of Fluorine.
– Fluoride has 10 electrons compared to nine electrons of fluorine and both have nine protons. Therefore, fluoride has a -1 charge, whereas fluorine is neutral.
– Fluoride has achieved the neon electron configuration, therefore, stable than the fluorine atom.
– The atomic radius of fluorine is 71 pm and the ionic radius of fluoride is 119 pm. The size of the anion has increased than the size of the atom, because the added electron shields the other electrons from the nucleus. Therefore, the attraction between the nucleus and the electrons reduces, giving a higher radius value to the Fluoride ion.