Menu
Other Resources

Compare Magnesium vs Aluminium

Comparing Magnesium (Mg) and Aluminium (Al). Atomic numbers 12 and 13 with atomic masses 24.304 u and 26.982 u, classified as alkaline earth metal and post-transition metal. Below: a side-by-side comparison of their physical, atomic, electron-configuration and historical properties, including density, melting and boiling points, ionization energies, oxidation states and discovery history.

vs
Mg
Magnesium
#12
Al
Aluminium
#13

Periodic properties of the elements

MagnesiumAluminium
SymbolMgAl
Atomic number1213
Group213
Period33
Blocksp
Element categoryAlkaline Earth MetalPost-Transition Metal

Physical properties

MagnesiumAluminium
Phase at STPSolidSolid
Density1.738 g/cm32.7 g/cm3
Atomic weight24.304 u26.9815 u
Melting point923 K
649.85 °C
1201.73 °F		933.47 K
660.32 °C
1220.576 °F
Boiling point1363 K
1089.85 °C
1993.73 °F		2743 K
2469.85 °C
4477.73 °F

Atomic properties

MagnesiumAluminium
Electronegativity (Pauling Scale)1.311.61
Electron affinity-40 kJ/mol41.762 kJ/mol
Oxidation states+1, +2
(a strongly basic oxide)		−2, −1, +1, +2, +3
(an amphoteric oxide)
Ionization energies
  1. 737.7 kJ/mol
  2. 1450.7 kJ/mol
  3. 7732.7 kJ/mol
  4. 10542.5 kJ/mol
  5. 13630 kJ/mol
  6. 18020 kJ/mol
  7. 21711 kJ/mol
  8. 25661 kJ/mol
  9. 31653 kJ/mol
  10. 35458 kJ/mol
  11. 169988 kJ/mol
  12. 189368 kJ/mol
  1. 577.5 kJ/mol
  2. 1816.7 kJ/mol
  3. 2744.8 kJ/mol
  4. 11577 kJ/mol
  5. 14842 kJ/mol
  6. 18379 kJ/mol
  7. 23326 kJ/mol
  8. 27465 kJ/mol
  9. 31853 kJ/mol
  10. 38473 kJ/mol
  11. 42647 kJ/mol
  12. 201266 kJ/mol
  13. 222316 kJ/mol

Electron configuration

MagnesiumAluminium
Shorthand configuration[Ne] 3s2 [Ne] 3s2 3p1
Full configuration1s2 2s2 2p6 3s2 1s2 2s2 2p6 3s2 3p1
Electrons per shell2, 8, 22, 8, 3

History

MagnesiumAluminium
PredictionAntoine Lavoisier (1782)
DiscoveryJoseph Black (1755)Hans Christian Ørsted (1824)
First isolationHumphry Davy (1808)
Named byHumphry Davy (1812)Humphry Davy (1812)
Compare Magnesium with
Compare Aluminium with