Atomic Element Z = 12 • Alkaline Earth Metal
Magnesium (Mg) — Atomic Data, Electron Shells & Reactions
Magnesium (symbol Mg, atomic number 12) has a standard atomic weight of 24.305 u and ground-state configuration [Ne] 3s2.
Atomic Number (Z)
12
IUPAC Symbol
Mg
Standard Atomic Weight
24.305 g/mol
Period / Group / Block
3 / 2 / s-block
Condensed Electron Config
[Ne] 3s2
Full Subshell Config
1s2 2s2 2p6 3s2
Principal Shell Occupancy
[2, 8, 2]
Pauling Electronegativity
1.31
First Ionization Energy
738 kJ/mol
Covalent Radius
141 pm
Melting Point
923 K (649.85 °C)
Boiling Point
1363 K (1089.85 °C)
Density
1.738 g/cm³
Oxidation States
+2
Mg (Z=12) — Valence shell highlighted in vermilion