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
$w-ZnO (or \beta ZnO$
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
$\geq Zn-O-$ 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 $g/cm^3$
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 $n_{\alpha}$
2.013
Refraction index $n_{\beta}$
2.029
Pure color
colorless
Color
white
Diaphaneity
translucent to subtranslucent
Luster
submetallic
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