Francium facts for kids

Neutral francium atoms can be trapped in the MOT using a magnetic field and laser beams.

Francium is a chemical element with the chemical symbol Fr and an atomic number of 87. It is a metal. In chemistry it is placed in a group of metal elements named the alkali metals. Francium is very radioactive. It has a half-life of 22 minutes. Francium is in very small amounts in uranium and thorium ores. It has the lowest electronegativity and electron affinity of all the chemical elements.

Francium reacts violently with water, as do all of the elements in group 1 on the periodic table.

Francium is one of the hardest to find elements on the planet Earth. It is estimated that there are only about 15 grams or half an ounce in the Earth's crust at a single time.

Although chemists knew the element number 87 in the periodic table should exist, it was a long time before it was discovered. In the early 1900s, nearly all boxes on the periodic table had been filled. Chemists knew that one element had been found to fit into each box. Francium was discovered in 1939 by a French chemist called Marguerite Perey. She named it after her home country, France.

Images for kids

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  This sample of uraninite contains about 100,000 atoms (3.3×10⁻²⁰ g) of francium-223 at any given time.

See also

In Spanish: Francio para niños