87 Fr 223
Francium
alkali metal
Properties
- Atomic number
- 87
- Atomic mass
- 223 u
- Category
- alkali metal
- Group
- 1
- Period
- 7
- Block
- s-block
- State (room temp)
- Solid
- Outer-shell electrons
- 1
- Electronegativity
- 0.79 (Pauling)
- Density
- 1.87 g/cm³
- Melting point
- 26.85 °C
- Boiling point
- 676.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s¹
Noble-gas shorthand: [Rn] 7s¹
Electrons per shell: 2, 8, 18, 32, 18, 8, 1 — that's 1 in the outermost shell.
About Francium
Francium is a chemical element with symbol Fr and atomic number 87. It used to be known as eka-caesium and actinium K. It is the second-least electronegative element, behind only caesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon.
- Discovered by Marguerite Perey
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.