Magnesium
A light structural metal that burns with a brilliant flame.
Inside the Magnesium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Magnesium atom step by step.
Electron configuration
[Ne] 3s2
A neutral Magnesium atom has 12 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 923 K (650 °C)
- Boiling point
- 1363 K (1090 °C)
- Density
- 1.738 g/cm³
- Electronegativity
- 1.31 Pauling
- Atomic radius
- 150 pm
- 1st ionization energy
- 738 kJ/mol
- Category
- Alkaline earth metals
Discovery & naming
- Discovered
- 1755
- Discovered by
- Joseph Black
- Origin of name
- From Magnesia, a district in Greece.
Notable uses
Lightweight structural alloys, flares, and dietary supplements.
Where Magnesium comes from
Stellar fusion and dying stars
Built by carbon and neon burning in the shells of massive stars.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 12
- Atomic mass
- 24.305
- Category
- Alkaline earth metals
- Group · Period
- 2 · 3
- Block
- s-block
- Shells
- 2 · 8 · 2