What is molecular formula of element Astatine and its use?

What is molecular formula of element Astatine? With an atomic number of 87, astatine is a naturally occurring radioactive element. It is found in trace amounts in Earth's crust and mantle and can also be produced artificially. This nuclide has 79 protons, 84 neutrons and 126 electrons, providing it with a mass number of 206. One mole of astatine weighs 18 amu (atomic mass units) or 28 g/mol while its atomic radius is 237 pm or 0.86 nm at room temperature.

Properties of element Astatine

1. Astatine is the heaviest naturally occurring element on Earth.

2. Astatine is a solid at room temperature, with a melting point of 45.2℃ (113℉).

3. It is chemically unreactive, with a half-life of 8.1 hours, which increases to 8 days in an oxygen atmosphere and decreases to 17 minutes in air; this also makes it difficult to detect.

4. It does not occur as a free element but only as the products of radioactive decay such as radon, polonium and bismuth astatide.

5. Astatine's most stable isotope, 211At has a half-life of 8.1 hours, decaying by alpha emission to bismuth.

6. Astatine is also named as At and 85.

7. Astatine was first produced in 1940 by irradiating bismuth with alpha particles, and the first stable isotope was discovered in 1972.

8. Astatine is one of the five rarest naturally occurring elements on Earth.

9. Only a few atoms of astatine are expected to be present at any given time throughout the Earth's crust and mantle as it has 'half life' of 8.1 hours, decaying via alpha decay to bismuth-211 and polonium-210 with a decay energy of 59840 keV (equivalent to 6983 kcal/mol)

10. The element's name is derived from the Greek word "astatos", which means "unstable."

Uses of element Astatine

1. Used in radiotherapy research.

Astatine is a non-radioactive alternative to phosphorous-32 used in radiation therapy. Phosphorus-32 decays to astatine within 10 hours at room temperature, generating a high rate of gamma-emission in the process. Astatine is still radioactive, but has a much longer half-life than 32P, so it is not expected to pose any serious risks during radioactive therapy routines. It also emits fewer high energy particles than 32P does when it undergoes alpha decay.

2. Used in cancer treatment.

The astatine is a promising cancer drug in Phase III clinical trials, but it is still not approved by the FDA. As of July 2015, radiotherapy using astatine has shown significant efficacy against gliomas without it being associated with side effects.

3. Used in gamma-ray emission spectroscopy.

Gamma rays are produced from many radioactive elements as they decay via alpha or beta decay to lighter isotopes or sometimes to other nuclides. Astatine is no exception to this, and it is also a radionuclide that can be used in gamma-ray emission spectroscopy. The newly discovered astatine isotope, 211At, can be used in the study of astatine and its decay.

4. Used in neutron activation analysis.

The neutron activation analysis (NAA) is one of the nuclear applications of astatine, in which a sample of a chemical mixture is irradiated with neutrons. This process is highly sensitive to nuclear isotope abundances, and it can be used to identify trace amounts of radioisotopes that may be present in the samples.

5. Used in bone research.

Scientists have recently discovered astatine's effects on bone. Molecular formula of element Astatine binds to the major histocompatibility complex, a protein that is expressed on the surface of cells present in the bone tissue and regulates immune responses. The presence of astatine leads to deactivation of this protein, reducing the process of inflammation in the tissue and thus diminishing calcium mobilization from bones. This mechanism may also be relevant to osteosarcoma, or other forms of skeletal tumors.

6. Used in cosmology.

It is believed that a small amount of astatine is produced in stars. In particular, the cosmic-ray spallation process may produce astatine. It has been suggested that such processes may then be responsible for the relatively high abundance of this very rare element in our solar system.

7. Used in radiometric dating.

Ionizing radiation, such as alpha particles and beta particles, can produce argon-40 from potassium-40, when the sample being dated contains enough potassium to allow its 40K atoms to decay via beta decay to 40Ar (argon).

Conclusion

What is molecular formula of element Astatine? Astatine is the rarest naturally occurring element on Earth. It is a synthetic, radioactive element and has no stable forms. Its atomic number is 87, and its symbol is At. One mole of astatine weighs 28 g/mol, and it has a atomic radius 237 pm. Astatine's main use today is in cancer treatment for solid tumors, though it also helps in radioisotope therapy research.