Francium facts for kids
Francium is a special chemical element that has the symbol Fr and the atomic number 87. It is a type of metal. In chemistry, francium belongs to a group of metals called the alkali metals.
Francium is very radioactive. This means it gives off energy as it breaks down. It has a very short "half-life" of just 22 minutes. This is the time it takes for half of a sample to decay. You can find tiny amounts of francium in uranium and thorium ores. It is also the element with the lowest electronegativity and electron affinity. This means it holds onto its electrons less tightly than any other element.
Like all alkali metals, francium reacts very strongly with water. This reaction can be quite explosive!
Francium is one of the rarest elements on Earth. Scientists believe there are only about 15 grams (which is about half an ounce) of francium in the Earth's crust at any one time. That's like finding a few tiny specks!
Even though chemists knew that element number 87 should exist on the periodic table, it took a long time to find it. By the early 1900s, almost all the spaces on the periodic table had been filled. Francium was finally discovered in 1939 by a French scientist named Marguerite Perey. She decided to name the new element after her home country, France.
| Group | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hydrogen & alkali metals |
Alkaline earth metals | Triels | Tetrels | Pnictogens | Chalcogens | Halogens | Noble gases |
||||||||||||
| Period |
|||||||||||||||||||
| 2 | |||||||||||||||||||
| 3 | |||||||||||||||||||
| 4 | |||||||||||||||||||
| 5 | |||||||||||||||||||
| 6 |  |
||||||||||||||||||
| 7 |  |
||||||||||||||||||
|
|||||||||||||||||||
|
|||||||||||||||||||
Primordial From decay Synthetic Border shows natural occurrence of the element
- Ca: 40.078 — Abridged value (uncertainty omitted here)
- Po: [209] — mass number of the most stable isotope
Images for kids
-
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
