Magnesium
Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (Group 2, or alkaline earth metals) of the periodic table:they each have the same electron configuration in their outer electron shell producing a similar crystal structure. Magnesium is the ninth most abundant element in the universe.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
10 is the [Ne] core total across two shells.
At a glance
- Atomic number
- 12
- Atomic mass
- 24.305 u
- Phase
- Solid
- Density
- 1.738 g/cm³
- Melting point
- 923 K
- Boiling point
- 1,363 K
- First ionization energy
- 737.7 kJ/mol
- Electronegativity
- 1.31
- Electron affinity
- -40 kJ/mol
- Molar heat capacity
- 24.869 J/(mol·K)
- Period
- 3
- Appearance
- shiny grey solid
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.