Cobalt(II) fluoride Cobalt(II) fluoride Cobalt(II) fluoride is a chemical compound with the formula (CoF). It is a pink crystalline solid compound which is antiferromagnetic at low temperatures (T=37.7 K) The formula is given for both the red tetragonal crystal, (CoF), and the tetrahydrate red orthogonal crystal, (CoF·4HO). CoF is used in oxygen-sensitive fields, namely metal production. In low concentrations, it has public health uses. CoF is sparingly soluble in water. The compound can be dissolved in warm mineral acid, and will decompose in boiling water. Yet the hydrate is water-soluble, especially the di-hydrate CoF·2H O and tri-hydrate CoF·3HO forms of the compound.
Chemical element than the current estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any naturally occurring element. The very heaviest 24 elements (those beyond plutonium, element 94) undergo radioactive decay with short half-lives and cannot be produced as daughters of longer-lived elements, and thus they do not occur in nature at all. The properties of the chemical elements are often summarized using the periodic table, which powerfully and elegantly organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties. The current standard table contains