CHEM-AD 102 Lecture Notes - Lecture 4: Acne Vulgaris, Ununseptium, Carl Wilhelm Scheele
Document Summary
Group 17 of the periodic table consists of nonmetallic elements known as halogens. The name halogen comes from the elements" ability to produce sodium salts. At stp, all of the elements exist as diatomic molecules. Halogens are highly reactive because they contain seven valence electrons. Because halogens are very reactive, they aren"t found free in nature. Halogen elements all raise the oxidation state of other elements. Fluorine was discovered and successfully isolated in 1886 by henri moissan. Fluorine has an atomic number of 9, an atomic mass of 18. 9984 amu, and an electron configuration of [he] 2s22p5. Fluorine has 18 isotopes with fluorine-19 is its only stable isotope. Fluorine-18, has a half life of 109. 771 minutes. 0. 054% fluorine naturally occurs in the earth"s crust. In addition, it also has the highest electronegativity of all the elements in the periodic table at 4. 0 on the. Fluorine in its elemental form is highly unstable and toxic.
