Francium (Fr) - Element 87 | Properties & Electron Configuration
What is Francium?
Francium (Fr) is element 87, a alkali metal in period 7, group 1. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s¹.
| Atomic Number | 87 |
| Symbol | Fr |
| Atomic Mass | 223 u |
| Category | Alkali Metal |
| Period | 7 |
| Group | 1 |
| Block | s |
| Electron Configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s¹ |
| Short Config | [Rn] 7s¹ |
| Electronegativity | 0.7 |
| Atomic Radius | N/A |
| Ionization Energy | 380 kJ/mol |
| Electron Affinity | N/A |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Francium is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s¹. In noble gas shorthand, this is written as [Rn] 7s¹.
Francium is a s-block element in group 1, period 7.
Periodic Trends
Electronegativity: Francium has a Pauling electronegativity of 0.7. Within group 1, electronegativity generally decreases down the group.
Ionization Energy: 380 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Francium on the Interactive Periodic TableRelated Topics
Hydrogen (H)
Properties of Hydrogen - same group as Francium
Lithium (Li)
Properties of Lithium - same group as Francium
Sodium (Na)
Properties of Sodium - same group as Francium
Radium (Ra)
Properties of Radium - same period as Francium
Actinium (Ac)
Properties of Actinium - same period as Francium
Thorium (Th)
Properties of Thorium - same period as Francium