Solid phase
Official name
Uranium dioxide
Secondary names
Uranium(IV) oxide; dioxouranium; Urania; Uranous oxide
CAS number
1344-57-6
Type
Family
ionic solid
Class
alkali salt
Compound type
oxide
Chemical composition
Formula
$U^{4+}O^{2-}_2$
Chemical formula
UO2
Elemental formula
(U) (O2-)2
Isotope mixture type
terrestrial abundance
6.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$U^{4+}$ Uranium cation element 1 0.3333333333333333 1 constituent cation main
$O^{2-}$ Oxide anion element 2 0.6666666666666666 1 constituent anion main
Chemical bonds
  Bond Number
$\cdot (\cdot) (\cdot) U^{4+} \cdot O^{2-} \cdot$ 8
Class
alkali salts (06)
Type
simple alkali salts (06.01)
Phase type
crystalline
Crystal system
isometric (cubic)
Crystal class
hexoctahedral
Crystal class symbol
m-3m (Oh)
Crystal spacegroup
Fm-3m
Molar mass
270.028 $g/mol$
Density
10.97 $g/cm^3$
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid liquid UO2 2865 °C (3138 K)
Refringence type
isotropic
Pure color
black
Color
black
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