Chemical element · Atomic number 12
Magnesium
Magnesium in the periodic table: atomic number 12, electron configuration, atomic mass, physical data, oxidation states, media credit and visible sources.
Alkaline earth metal
solid
24.305 u
Documented element sampleCrystals of elemental magnesium produced by vapor deposition.
Image credit: Warut Roonguthai
Auto-oriented, limited to 1600 × 1200 pixels and re-encoded as WebP; the subject was not altered.
Atomic classification
Shell occupancy
Magnesium in the Bohr shell model
This shows the electron distribution of the neutral atom in a simplified shell model.
- K · n=1
- 2 electrons
- L · n=2
- 8 electrons
- M · n=3
- 2 electrons
- Electron configuration
- [Ne]3s2
- Electrons per shell
- 2 · 8 · 2
- Group
- 2
- Period
- 3
- Block
- S
- Element category
- Alkaline earth metal
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Physical and chemical properties
- Atomic mass
- 24.305 u
- Standard state
- solid
- Density
- 1.74 g/cm³
- Melting point
- 923 K
- Boiling point
- 1,363 K
- Electronegativity
- 1.31 (Pauling)
- First ionisation energy
- 7.646 eV
- Oxidation states
- +2
- Discovery
- 1808
Safety and periodic classification
Safety
Safe handling cannot be inferred from Magnesium's position in the periodic table alone. Laboratory, classroom and disposal decisions must follow the documentation for the exact material and its safety data sheet.
Position and comparison
Magnesium is in period 3, group 2 and the S block. Its direct neighbours by atomic number are Sodium and Aluminum. The recorded Pauling electronegativity is 1.31. Periodic trends are compared only through the separately sourced neighbouring values.
Sources and scope
PubChem attributes element data to sources including IUPAC, NIST and IAEA. Quanta stores the referenced snapshot locally and leaves unknown values unavailable.