Magnesium oxide facts for kids

Quick facts for kids Magnesium oxide
IUPAC name	Magnesium oxide
Other names	Magnesia Periclase
Identifiers
CAS number	1309-48-4
PubChem	14792
EC number	215-171-9
RTECS number	OM3850000
Properties
Molecular formula	MgO
Molar mass	40.304 g/mol
Appearance	White powder
Odor	Odorless
Density	3.6 g/cm3
Melting point	2852 °C, 3125 K, 5166 °F
Boiling point	3600 °C, 3873 K, 6512 °F
Solubility	Soluble in acid, ammonia insoluble in alcohol
Band gap	7.8 eV
Magnetic susceptibility (χ)	−10.2·10−6 cm3/mol
Thermal conductivity	45–60 W·m−1·K−1
Refractive index (nD)	1.7355
Dipole moment	6.2 ± 0.6 D
Structure
Crystal structure	Halite (cubic), cF8
Space group	Fm3m, No. 225
Lattice constant	a = 4.212Å
Coordination geometry	Octahedral (Mg2+); octahedral (O2−)
Thermochemistry
Std enthalpy of formation ΔfHo298	−601.6 ± 0.3 kJ·mol−1
Standard molar entropy So298	26.95 ± 0.15 J·mol−1·K−1
Specific heat capacity, C	37.2 J/mol K
Pharmacology
ATC code
Hazards
Main hazards	Metal fume fever, Irritant
NFPA 704	0 1 0
R-phrases	R36, R37, R38
Flash point	Non-flammable
U.S. Permissible exposure limit (PEL)	TWA 15 mg/m3 (fume)
Related compounds
Other anions	Magnesium sulfide
Other cations	Beryllium oxide Calcium oxide Strontium oxide Barium oxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Magnesium oxide, or magnesia, is a white solid mineral, made of one part magnesium and one part oxygen. Its chemical formula is MgO. Magnesium oxide is used by libraries to make books last longer. It is also used as an insulator for some electrical wires, and to help crucibles resist high temperatures. Magnesium oxide is also used to treat heartburn and upset stomachs.

Images for kids

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  Unpolished MgO crystal

See also

In Spanish: Óxido de magnesio para niños