87Fr[223]
Francium
Alkali metalsSoft, very reactive metals with one outer electron. They react with water to make alkaline solutions.
[Rn] 7s¹
- Atomic number
- 87
- Atomic mass
- [223]
- Protons
- 87
- Neutrons
- 136
- Electrons
- 87
- Shells
- 2, 8, 18, 32, 18, 8, 1
- State at 25 °C
- Solid
- Position
- Group 1, period 7
Proton (+)Neutron (0)Electron (−)
Discovered byMarguerite Perey, 1939Marguerite Perey: 1 element
Perey, who worked in Marie Curie's institute, found it and named it after France. It was the last element found in nature.
Did you know?
- Its longest-lived form has a half-life of about 22 minutes.
- Only a few tens of grams exist on Earth at any moment.
Where it's found
- Tiny traces in uranium ores
What it's used for
- Scientific research only
Try it
There's no safe home experiment for Francium. Explore it with the animated atom above instead.