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Francium (Fr)
Atomic number: 87 · Category: alkali metal · Group 1 · Period 7 · Phase: Solid
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.
Block: s
CPK color:#420066
Electronic structure
Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s1
Configuration (semantic): [Rn] 7s1
Shells: 2, 8, 18, 32, 18, 8, 1
Electronegativity (Pauling): 0.79
Electron affinity: 46.89
Ionization energies: 380
Periodic position
Group: 1
Period: 7
xpos: 1
ypos: 7
Spectral/Bohr images
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3D Model