Electron Configuration of Beryllium (Be)
What is the electron configuration of Beryllium?
The electron configuration of Beryllium (Be, Z=4) is 1s² 2s². In noble gas shorthand: [He] 2s². It has 0 unpaired electron(s) and is a s-block element.
| Symbol | Be |
| Atomic Number | 4 |
| Full Electron Configuration | 1s² 2s² |
| Noble Gas Shorthand | [He] 2s² |
| Block | s |
| Period | 2 |
| Group | 2 |
| Unpaired Electrons | 0 |
| Exception? | No |
Orbital Filling Order
Following the aufbau principle, the 4 electrons in Beryllium fill orbitals in order of increasing energy: 1s (2 electrons), then 2s (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 Beryllium match the configuration of He. This allows us to abbreviate the configuration as [He] 2s², where [He] represents the filled core and the remaining entries show the valence electrons.
Valence Electrons
The valence shell of Beryllium contains 2 electrons in the 2s subshell. These outermost electrons determine Beryllium's chemical reactivity, bonding behavior, and position in the periodic table as a s-block element in period 2.
Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.
Explore Beryllium in the Electron Configuration ExplorerRelated Topics
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Orbital filling for Hydrogen (s-block)
Electron Configuration of Helium
Orbital filling for Helium (s-block)
Beryllium on the Periodic Table
Full properties and periodic trends for Beryllium
Orbital Hybridization
See how atomic orbitals mix to form sp, sp2, and sp3 hybrids