ELEMENTLE

Element 12 · Alkaline Earth Metal

Magnesium

Period 3 · Group 2

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.

Three reasons Magnesium stands out

  1. 1

    Used in alloys and as a structural metal.

  2. 2

    It burns with a blinding white light so intense it can cause permanent eye damage.

  3. 3

    It sits at the centre of every chlorophyll molecule, making photosynthesis possible.

A bright metal at the center of green life

Magnesium burns with an intense white light, a property once exploited in flash photography and still used in flares. In biology it occupies the center of chlorophyll, helping plants capture sunlight. Its low-density alloys reduce weight in vehicles and devices without giving up useful strength.

Magnesium at a glance
Atomic number / protons12
SymbolMg
Family (Elementle)Alkaline Earth Metal
Classification (PubChem)Alkaline earth metal
Period3
Group2
Atomic mass (u)24.305
Standard stateSolid
Electron configuration[Ne]3s2
Reported oxidation states+2
Electronegativity (Pauling)1.31
Atomic radius (pm)173
First ionization energy (eV)7.646
Electron affinity (eV)Not available
Density (g/cm³)1.74
Melting point923 K (649.85 °C)
Boiling point1363 K (1,089.85 °C)
Discovery (PubChem)1808

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Magnesium · Magnesium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.