Fr francium Element-Origin Context

ID: element.fr.origin

Represents francium (Fr, Z=87) as a periodic-table element with bounded origin-family context.

Status: canonical_reference

Uncertainty

• This canonical_reference badge is a theory locator; its claim still needs independent, claim-specific validation.

Sources

• https://doi.org/10.18434/T4W30F
• https://doi.org/10.1103/RevModPhys.29.547
• https://doi.org/10.1103/RevModPhys.93.015002
• 2020ApJ...900..179K

Claim boundaries

• This badge locates a theory claim; it does not validate a physical effect or engineering application.

Diagnostic context only. Cite independent evidence for claims about the world.