Solid phase
Official name
Triuranium octoxide
Secondary names
Uranium(V,VI) oxide; Uranium octoxide; Uranyl uranate; Pitchblende; U3O8
CAS number
1344-59-8
Type
Family
covalent network solid
Class
tridimentional covalent network solid
Compound type
oxide
Chemical composition
Formula
U3O8
Chemical formula
U3O8
Elemental formula
U3 O8
Isotope mixture type
terrestrial abundance
22.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
U Uranium element 3 0.2727272727272727 1 constituent element main
O Oxygen element 8 0.7272727272727273 1 constituent element main
Chemical bonds
  Bond Number
>>U−O−
≥>U−O−
Class
tridimensional covalent networks (11)
Type
two non-metal (or one metalloid and one non-metal) atoms tridimensional networks (Ceramics) (11.03)
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
pyramidal
Crystal class symbol
mm2 (C2v)
Crystal spacegroup
Amm2
Molar mass
842.08 g/mol
Density
8.3 g/cm3
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid liquid 1150°C (1420 K)
Refringence type
biaxial
Pure color
gray
Color
gray, olive green, black
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