Solid phase
Official name
Zinc oxide
Secondary names
hexagonal Zinc oxide; w-ZnO; beta-ZnO; wurtzite ZnO
CAS number
1314-13-2
Type
Family
covalent network solid
Class
tridimentional covalent network solid
Compound type
oxide-hydroxide
Comments
ZnO can be almost considered as an alkali salt (largely ionic bonding)
Chemical composition
Formula
w−ZnO(orβZnO
Chemical formula
ZnO
Elemental formula
Zn O
Isotope mixture type
terrestrial abundance
4.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
Zn Zinc element 1 0.5 1 constituent element main
O Oxygen element 1 0.5 1 constituent element main
Chemical bonds
  Bond Number
≥Zn−O− 4
Class
tridimensional covalent networks (11)
Type
metal homonuclear tridimensional networks (elemental) (11.02)
Phase name
w-ZnO, beta-ZnO
Phase type
crystalline
Crystal system
hexagonal
Crystal class
dihexagonal-pyramidal
Crystal class symbol
6mm (C6v)
Crystal spacegroup
P6(3)mc
Comments
the bonding in ZnO is largely ionic (Zn^{2+}–O^{2−})
Molar mass
81.406 g/mol
Density
5.1 g/cm3
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid Zn, O gases 2247K (1974°C)
Phase transitions comments
decomposes at 2247K
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.016
Refraction index nα
2.013
Refraction index nβ
2.029
Pure color
colorless
Color
white
Diaphaneity
translucent to subtranslucent
Luster
submetallic
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