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LITHOEN

Chemical element

Uranium

A radioactive trace element whose decay both heats the Earth and provides its most precise clocks.

Classification

atomic number
92
symbol
U
block
f

How this record is known

3
Settled consensus
Cited as the accepted position of the discipline.

3 of 3 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

Established92 protons

Uranium has atomic number 92: its nucleus contains 92 protons, and that is what makes it uranium.

  • definition basis: Atomic number is definitional: an atom with a different proton count is a different element, whatever else it shares.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

Established238.02891 u

The standard atomic weight of uranium is 238.02891(3), a single value because its isotopic composition does not vary appreciably between normal materials.

  • definition basis: CIAAW Standard Atomic Weights 2024; the parenthesised digits are the uncertainty in the last figures as published.
  • precision note: A property of the element as found in normal materials, not the mass of any individual atom.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

In the knowledge graph

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.