Electron Configuration of Magnesium (Mg)
What is the electron configuration of Magnesium?
The electron configuration of Magnesium (Mg, Z=12) is 1s² 2s² 2p⁶ 3s². In noble gas shorthand: [Ne] 3s². It has 0 unpaired electron(s) and is a s-block element.
| Symbol | Mg |
| Atomic Number | 12 |
| Full Electron Configuration | 1s² 2s² 2p⁶ 3s² |
| Noble Gas Shorthand | [Ne] 3s² |
| Block | s |
| Period | 3 |
| Group | 2 |
| Unpaired Electrons | 0 |
| Exception? | No |
Orbital Filling Order
Following the aufbau principle, the 12 electrons in Magnesium fill orbitals in order of increasing energy: 1s (2 electrons), then 2s (2 electrons), then 2p (6 electrons), then 3s (2 electrons).
Each orbital is filled according to the Pauli exclusion principle (at most 2 electrons per orbital) and Hund's rule (electrons occupy degenerate orbitals singly before pairing).
Noble Gas Shorthand
The inner electrons of Magnesium match the configuration of Ne. This allows us to abbreviate the configuration as [Ne] 3s², where [Ne] represents the filled core and the remaining entries show the valence electrons.
Valence Electrons
The valence shell of Magnesium contains 2 electrons in the 3s subshell. These outermost electrons determine Magnesium's chemical reactivity, bonding behavior, and position in the periodic table as a s-block element in period 3.
Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.
Explore Magnesium in the Electron Configuration ExplorerRelated Topics
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Electron Configuration of Hydrogen
Orbital filling for Hydrogen (s-block)
Electron Configuration of Helium
Orbital filling for Helium (s-block)
Magnesium on the Periodic Table
Full properties and periodic trends for Magnesium
Orbital Hybridization
See how atomic orbitals mix to form sp, sp2, and sp3 hybrids