#87
Francium
alkali metal· Solid·223 u
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.
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Identity
- Symbol
- Fr
- Atomic Number
- 87
- Atomic Mass
- 223 u
- Category
- alkali metal
- Block
- s-block
- Period
- 7
- Group
- 1
- Appearance
- Chemical element with atomic number 87 (Fr)
- Year Discovered
- 1939 CE
- Discovered By
- Marguerite Perey
- Named By
- France
Electrons
- Configuration
- [Rn] 7s1
- Full Configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s1
- Shells
- 2, 8, 18, 32, 18, 8, 1
- Electronegativity
- 0.79
- Electron Affinity
- 46.89
- Oxidation States
- +1
- Ionization Energies
- 380
Physical Properties
- State at
- Solid
- Melting Point
- 300
- Boiling Point
- 950
- Density
- 1.87
- Crystal Structure
- BCC
- Magnetic Ordering
- Paramagnetic
Mechanical
- Covalent Radius
- 260 pm
- Van der Waals
- 348 pm
- Metallic Radius
- 270 pm
Thermal & Electrical
- Specific Heat
- 131 J/(kg K) J/(g·K)
- Heat of Vaporization
- 65 kJ/mol kJ/mol
- Heat of Fusion
- 2 kJ/mol kJ/mol
Abundance
- Universe
- 0
- Sun
- 0
- Meteorite
- 0
- Earth's Crust
- 1e-18 ppm
- Ocean
- 0
- Human Body
- 0