Francium

Francium (symbol Fr, atomic number 87) is a radioactive chemical element classified as an alkali metal. It is extremely rare, occurring in trace amounts in uranium and thorium ores, where it is formed as an intermediate decay product. All isotopes of francium are highly radioactive and short-lived; the most stable isotope, francium-223, has a half-life of only 21.8 minutes.

History:

Francium was discovered in 1939 by Marguerite Perey at the Curie Institute in Paris. Perey purified a sample of actinium-227 and noticed that it decayed into a previously unknown radioactive element. She named the new element "francium" in honor of her native France. It was the last element discovered in nature before the synthesis of heavier elements.

Properties:

Due to its extreme rarity and radioactivity, very little is known about the bulk properties of francium. It is predicted to exhibit properties similar to those of other alkali metals, such as cesium. It is expected to be a highly reactive metal that reacts vigorously with water. It is also expected to have a low melting point and boiling point.

• Atomic Symbol: Fr
• Atomic Number: 87
• Atomic Weight: [223] (most stable isotope)
• Element Category: Alkali Metal
• Electron Configuration: [Rn] 7s¹
• State at Room Temperature: Solid (predicted)
• Melting Point: Estimated to be around 21 °C (70 °F) – estimated based on trends in alkali metals.
• Boiling Point: Estimated to be around 677 °C (1251 °F) – estimated based on trends in alkali metals.
• Density: Estimated to be around 2.4 g/cm³ - estimated based on trends in alkali metals.

Occurrence:

Francium occurs in uranium and thorium minerals as a product of alpha decay. It is estimated that there is only about 340 grams of francium present in the Earth's crust at any given time.

Isotopes:

There are 34 known isotopes of francium, all of which are radioactive. Francium-223 is the most stable isotope, with a half-life of 21.8 minutes. Other notable isotopes include francium-221 (half-life 4.8 minutes) and francium-222 (half-life 14.2 minutes).

Uses:

Due to its rarity and radioactivity, francium has no commercial applications. It is used primarily for research purposes in the fields of chemistry and atomic physics. Studies of francium have provided information on atomic structure and the electroweak interaction. Some experiments use trapped francium atoms to study fundamental symmetries and the search for violations of the Standard Model of particle physics.

Precautions:

Francium is highly radioactive and must be handled with extreme care. Exposure to francium can cause radiation sickness and increase the risk of cancer.