Strontium is an element with atomic symbol Sr, atomic number 38, and atomic weight 87.62.
Strontium atom is an alkaline earth metal atom.
Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is either referred to as stable strontium or strontium.
Strontium in the environment exists in four stable isotopes, 84Sr (read as strontium eighty-four), 86Sr, 87Sr, 88Sr. Strontium compounds are used in making ceramics and glass products, pyrotechnics, paint pigments, fluorescent lights, and medicines.
Strontium can also exist as several radioactive isotopes; the most common is 90Sr. 90Sr is formed in nuclear reactors or during the explosion of nuclear weapons.
Radioactive strontium generates beta particles as it decays. One of the radioactive properties of strontium is half-life, or the time it takes for half of the isotope to give off its radiation and change into another substance. The half-life of 90Sr is 29 years.
Fluorine is a chemical element with the symbol F and atomic number 9.
It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with almost all other elements, except for helium and neon.
Fluorocarbon gases are generally greenhouse gases with global-warming potentials 100 to 20,000 times that of carbon dioxide.
Organofluorine compounds often persist in the environment due to the strength of the carbon–fluorine bond. Fluorine has no known metabolic role in mammals; a few plants and sea sponges synthesize organofluorine poisons (most often monofluoroacetates) that help deter predation.