Francium

Francium
General Info
Atomic Symbol	Atomic symbol::Fr
Atomic Number	Atomic number::87
Atomic Weight	Atomic weight::223.019 g/mol
Chemical series	Alkali Metal
Appearance	A picture of what the element Francium looks like.
Group, Period, Block	1, 7, s
Electron configuration	[Rn] 7s
Electrons per shell	2, 8, 18, 32, 18, 8, 1
CAS number	CAS number::7440-73-5
Physical properties
Phase	solid
Density	Density::N/A g/ml
Melting point	Melting point::27 °C
Boiling point	Boiling point::677 °C
Isotopes of Francium
iso NA half-life DT DE (MeV) DP 210Fr syn 3.2m αto 206At; EC to 210Rn 211Fr syn 3.10 m αto 207At; EC to 211Rn 212Fr syn 20 m α to 208At; EC to 212Rn 213Fr syn 34.6 s α to 209At; EC to 213Rn 214Fr syn 0.0051 s α to 210At 215Fr syn 0.0000012 s α to 211At 216Fr syn 0.000007 s α to 212At; EC to 216Rn 217Fr syn 0.00016 s α to 213At 218Fr syn 0.001 s α to 214At 219Fr syn 0.021 s α to 215At 220Fr syn 27.4 s α to 216At; β- to 220Ra 221Fr syn 4.8 m α to 217At; β- to 221Ra; 14C 222Fr syn 14.3 m β- to 222Ra 223Fr nil 22 m α to 219At; β- to 223Ra 224Fr syn 3 m β- to 224Ra 225Fr syn 3.9 m β- to 225Ra 226Fr syn 49 s β- to 226Ra 227Fr syn 2.48 m β- to 227Ra
All properties are for STP unless otherwise stated.

Francium is a chemical element that is part of the Alkali metal family and known by the chemical symbol Fr. Only a small amount of it is found in the Earth's crust. It is one of the most unstable elements that is found naturally and only has a lifespan of about 22 minutes. As a result, many of its properties are estimated. It was founded by Marguerite in 1939 and is formed in particle accelerators also known as atom smashers. Francium has no uses, other than chemistry research.

Properties

Francium is part of the alkali metals. It has silver-gray metallic color. It also has a valence electron of one. Francium is not a very common element because its chemical and physical properties have not been fully discovered. Its most stable state is the ion Fr+. One thing that is known is the fact that it is the least electronegative of all the elements discovered on the periodic table.

Francium is also the heaviest known element in the alkali metal series and has the highest weight, greater than any other element on the periodic table. Francium is, not only is the heaviest, but also is the most unstable of the first 101 elements of the periodic table. All of its isotopes are unstable too. This means that radiochemical methods can not determine their chemical properties. As well as no quantifiable amount has been isolated yet. The chemical properties of francium that are known (as of now) seem to closely resemble Cesium.

Synthesis

Francium atoms as they are held in the trap.

Francium has been synthesized in particle accelerators(atom smasher). This stimulates tiny particles, such as protons, at 186,000 miles a second. Then these tiny little particles smash into target atoms. Atoms such as copper, tin, and gold. Then these atoms break apart and create other atoms or particles. At the State University of New York at Stony Brook, they are doing important work on Francium. Scientist, at the university, have discovered ways to trap some of the francium atoms into a magnetic field. Once in the magnetic field it can be held there long enough for scientist to take the measurements they need.

Francium is formed from the radioactive decay of actinium. Francium is usually found in uranium minerals or can be artificially made by adding protons to thorium. Francium is very unstable, but its longest living isotope is ²²³Fr. This isotope has a half-life of 22 minutes and is the only one that occurs in nature. Francium is so rare that there is only about 20-30 grams of it that exist in the Earth's crust.

History

Marguerite Perey, a French Radiochemist who found Francium.

Marguerite Perey discovered the element, francium in 1939. She found it while doing some research on actinium's decaying process. Since she was a French chemist, she named it after her country, France. For years and years chemists had been searching for this element. Probably since Dimitri Mendeleev's time. Francium was a hard element to isolate because it is radioactive and only has a life span of 21 minutes. It is amazing she discovered francium at all.

Perey was also the first woman allowed a two-hundred year old academy that even Marie Curie could not get into. Marie Sklodowska Curie instructed Perey when she took a job at the Institut du Radium in 1929. Marguerite helped chemistry in many ways. Like when she founded a laboratory for students and colleagues after she had been chosen as a instructor at Université of Strasbourg in 1949. The laboratory she founded the Laboratiore de Chimie Nucléaire in the Centre de Recherches Nucléaires in 1958 and she became the director for it. Marguerite Perey added to the science world by being a part of chemistry and finding a missing piece to the puzzle of the periodic table. .

More Facts on Francium

Francium is a very interesting element and there is a great deal of facts that some people might not know. For instance, scientists thought that there might be one more in the Alkali Family and that cesium was not the end. Even a number of them anticipated it would have an atomic number of 87 all the way back in 1870s. Prior to the discovery of this element it had been called eka-caesium. Before Marguerite Perey founded it, there were four false reports that chemists had found it, but indeed they did not. Francium is also the most unstable naturally occurring element. Since it is unstable and cannot be found easily, since only a small amount exists, most of its properties have to be estimated. This also means that Francium has no uses since it does not last long. This element is very different in every aspect from the rest of it family and other elements.

Video

Francium - Periodic Table of Videos