Francium Facts

Francium is a heavy alkali metal. In the periodic table, it is positioned in the last row (or seventh period) of group IA. Chemically, it is represented with the symbol Fr. Interestingly, among all the naturally occurring elements that are found on the surface of the earth, the last element that was discovered by mankind was francium. The credit for discovering this metallic element goes to French physicist Marguerite Perey. In 1939, when she was working in Curie Institute in Paris, France, she analyzed the radioactive decay of element actinium. At that time, she observed that almost 99 percent of actinium disintegrates into thorium and the rest of the one percent changes into an element which has atomic number 87. She named this newly discovered element francium after her motherland France where it was discovered.

Physical Properties

Some of the important physical characteristics that distinguish francium from other chemical elements are as follows:

• Standard state (phase): Solid
• Color: Metallic
• Melting point: 300K or 27 °C or 80 °F
• Boiling point: 950K or 677 °C or 1250 °F
• Density: 1.87g per cubic centimeter

Chemical Properties

The distinguishing features about the atoms of this element determine its chemical properties. A few of them are listed below:

• Atomic number: 87
• Atomic mass: 223.0197
• Electrons per shell: 2,8,18,32,18,8,1
• Oxidation state: 1 (strong basic oxide)

Trivia

Francium is extremely rare in nature. In fact, it is the second rarest element after astatine. Experienced researchers believe that there are hardly 30 grams of francium found on the surface of the earth. Natural form of francium is available in trace amounts with uranium and thorium minerals. It can also be obtained by artificial means where thorium atoms are bombarded with fast-moving protons. It can be produced by bombardment of radium atoms with neutrons too.

One of the most interesting francium facts is that its electronegativity is the lowest among all the chemical elements that are available. For this reason, it is highly reactive in nature. Since, it is not found in larger quantities not many practical information is available about its chemistry. Theoretically, it has been proved that it is the most chemically active alkali metal. It would react violently with water. This reaction is going to be more vigorous than the reaction between sodium and water.

Francium is a radioactive metal. In other words, it has a very unstable nucleus. The half-life period of this radioactive element is barely 22 minutes. On radioactive disintegration, it decays into astatine, radium, and radon.

In all, there are 34 isotopes of francium. The atomic mass of these isotopes lies in between 199 and 232. Out of them, only two are naturally occurring isotopes of francium. They are: francium-223 and francium-221. Francium 223 is more commonly found as it is comparatively more stable. All the remaining 32 isotopes are produced artificially.

There are no francium uses for commercial purposes. This is mainly because of the fact that it is not easily available and its half-life period is very short. Its uses are mostly confined to research laboratories where it is studied to gather information about its atomic structure and possible biological uses.

So far, there are no known adverse effects of this element on human health. However, due to its radioactivity, it emits harmful radiations which are hazardous to our health. So, it should be handled with great care in order to prevent any exposure.